The UK has very strict laws about what you can and can't do with other people's data. If you intercept it so that you can see what it is, deliberately delay its transmission or prevent it from reaching its destination altogether, you can be fined or thrown in prison.

Unfortunately, that only applies if the data is written down and sent through the post. If it's electronic and you're an ISP, you can filter, delay and even block data all day long.

Our connections are already monitored and filtered to prevent us from stumbling across horrific and illegal images, but there's growing pressure for ISPs to do more.

As we'll discover, ISPs could soon be stopping us viewing perfectly legitimate content, with secret blacklists making some sites disappear.

The way we consume content is changing. Increasingly, news comes not in newsprint, but via RSS feeds, video services and smartphone apps. Radio has turned into something we stream or download, we're more likely to watch TV via iPlayer or 4oD than tune in at a particular time to watch a specific programme, and most of us would rather download a film than visit one of the few remaining video shops.

That means most of the information you access comes down a single pipe: your home broadband connection. We assume that ISPs don't meddle with our connections, but is that true? Could ISPs filter what we see and do online, censor websites and prioritise some kinds of content over others?

They already do. Many ISPs throttle traffic like the BBC's iPlayer at peak periods, and BitTorrent users will be well aware that ISPs don't treat all kinds of data equally.

As Trefor Davies, Chief Technical Officer of Timico and council member of the UK Internet Service Providers Association, explains: "traffic management varies from ISP to ISP, with some not doing it and others managing the heck out of users' traffic.

It's a commercial issue. If someone wants to pay a rock-bottom price for a broadband service then their ISP is probably not going to want to spend lots of money providing lots of bandwidth capacity."

Traffic management

In practice, this sort of traffic management usually means that bandwidth hogs like BitTorrent are restricted to prevent other services like Skype from becoming unusable.

"Most - if not all - ISPs try to give priority to time-critical applications such as voice, gaming and so on," Davies explains. "You usually hear complaints about traffic management when people are hitting torrents hard and the torrent, which is a very inefficient use of a network, slows to a dribble," he adds.

Could the same technology be used for ill - for example, by crippling competitors to give ISPs' own services a helping hand?

In March, Culture Minister Ed Vaizey told reporters the three principles he believes should guide the way ISPs act. "The first is that users should be able to access all legal content," he said. "Second, there should be no discrimination against content providers on the basis of commercial rivalry. And finally, traffic management policies should be clear and transparent."

Vaizey was commenting on the launch of the Broadband Stakeholders Group's new code, to which BSkyB, BT, O2, TalkTalk, Three, Virgin Media and Vodafone are signatories. However, the code isn't really about traffic management - it's about how ISPs communicate details of their traffic management to consumers.

The BSG isn't promising that ISPs won't penalise specific services; it's just promising that if they do, they'll tell you about it "in a common format". The principle that ISPs shouldn't discriminate on the basis of commercial rivalry is open to interpretation. The big ISPs aren't just carriers - they're service and content providers too. For example, TalkTalk sells domestic telephone services.

Would managing Skype or other voice over IP applications be seen as commercial rivalry? BT and Virgin Media are planning to launch new music services. Would throttling Spotify, Amazon's Cloud Player or the forthcoming cloud-based iTunes be commercial rivalry? Many ISPs offer video on demand. Would it be deemed discrimination on the basis of commercial rivalry if they managed H.264 video streams, or iTunes downloads, or BitTorrent?

We regulate old media - for example, we regulate broadcasting so that one company can't own too many TV stations, radio stations and newspapers simultaneously - and today, much of the media we consume is delivered via our broadband connections.

It's conceivable that traffic management could be used by ISPs to abuse their power, so should we regulate new media to prevent that? Does the concept of net neutrality - where data is treated identically no matter where it comes from - need to be enshrined in law?

The government's answer is no.

Neutral on neutrality

Speaking at the FT World Telecoms Conference in November, Ed Vaizey said that: "a lightly regulated internet is good for business, good for the economy and good for people [...] The government is no fan of regulation and we should only intervene when it is clearly necessary to deliver important benefits for consumers."

Peter Bradwell is a campaigner with the Open Rights Group. "Net neutrality does encompass some familiar questions of media plurality," he says, "and this is of vital importance to the future of the internet. The question is, how do you ensure that it remains a fair marketplace in which incumbents are consistently challenged by new entrants, and that regardless of stature or wealth, people can distribute their ideas, information and services to the world? Our belief is that allowing ISPs to make deals with content providers - deals that privilege incumbents' data - could put that at risk."

Michael Jarvis, head of retail media relations at BT, argues that ISPs would quickly be punished by customers for any such deals.

"No ISP has any market power in the UK, and therefore none have the power to shape or view what we see and do online. If any ISP tried to do so and their customers didn't like it, they could easily move to a competing ISP," he says.

"BT cannot answer for other ISPs, but we have four key public commitments: BT broadband customers will be able to access any internet-based service or application; no legal service or application will be blocked on these products; content and application providers will not be charged for basic internet conveyance; and we will provide wholly transparent information to customers on our traffi c management practices in line with industry best practice."

Our ISPs aren't in the censorship business, but if the government gets its way, that may soon change.

ISPs don't censor the internet, with a few notable exceptions: since the Demon vs Godfrey case in 2001, ISPs have been legally obliged to remove allegedly defamatory material from their servers or face prosecution, and many mobile phone connections have adult content filters switched on by default to stop children accessing content they shouldn't.

The main exception is child pornography, which ISPs block by default. Websites are usually blocked in one of two ways: DNS filtering or blacklists. DNS filtering is the simplest method, but it can be a very blunt instrument.

When you block a specific site by its IP address, you also block any of its subdomains. This is how US authorities wrongly blocked some 84,000 subdomains last year, replacing their websites with notices claiming that they were involved in illegal pornography.

The other common approach, content filtering, is less likely to block legitimate websites. Instead of simply blocking IP addresses, content filtering checks requested URLs against a database of known sites.

If the URL isn't on the list, the page appears normally. If the URL is on the list, the traffic is routed to proxy servers that perform a more detailed check. If the URL passes this test, the requested page or file is shown. If it doesn't, the browser is redirected to a warning page or 'Page not found' message instead of the requested content.

That's how Cleanfeed, BT's illegal content filter, works. The blocklist comes courtesy of the Internet Watch Foundation, and it only checks for content that's been identified as child pornography. The IWF also monitors the internet for other material, including incitement to violence, hate speech and other obscene content, but that content isn't included on its URL blocklist.

All ISPs - including mobile phone data networks - have been required by law to use this kind of filtering since 2008. The big advantage of the Cleanfeed system is its precision. For example, it can block a single page or file and leave the rest of a website untouched.

Like any system, though, it isn't perfect: in 2008 it emerged that the IWF blocklist included a Wikipedia page about The Scorpions' album Virgin Killer, whose controversial artwork was deemed illegal under UK law. The blocklist censored the page describing the artwork, but not the artwork itself, and it temporarily prevented users of Cleanfeed-subscribing ISPs from updating any entries on Wikipedia whatsoever.

Mission creep

Despite the odd problem, few people would argue that filtering child pornography is a bad thing. However, any kind of site-blocking suffers from mission creep: if we can filter one type of content, politicians and pressure groups ask, why can't we filter another?

The most extreme example of such mission creep is in Australia. Its Labor Party wants ISPs to block any content that isn't suitable for under-15s, and which isn't protected by effective age verification systems, and its politicians have proposed that ISPs should also block euthanasia and anorexia websites, sites about illegal drugs, sites about abortion, overseas online gambling and so on.

Such mandatory filtering would be based on the ACMA (Australian Communications and Media Authority) blacklist, which, if the leaked version posted on Wikileaks is genuine, includes a dental surgery, a dog kennel and a travel agency. Could similar filtering happen here?

In 2006, Home Office minister Vernon Croaker admitted that the government had considered legislation forcing ISPs to block sites "glorifying terrorism" under the Terrorism Act 2006, while in December Ed Vaizey told the Sunday Times that ISPs should block all legal pornography by default "to protect children".

"I am hoping they will get their acts together so we don't have to legislate," Vaizey said. If you've ever run up against your phone provider's adult content filter while trying to access a perfectly reputable and non-pornographic website, you'll know that such filtering already happens and often tends to be overzealous.

In addition to filtering adult content, the government would like ISPs to filter another kind of content. In April, the culture minister met with ISPs to discuss the creation of an IWF-style blacklist - this time to filter sites accused of copyright infringement.

Secret blocks

"Website blocking is not straightforward," Trefor Davies says. "Consumer ISPs blocking the IWF list are only having to deal with around 600 URLs, updated twice daily. Having to gear up to cope with what are potentially hundreds of thousands of sites is another cost dimension again. The other issue is who takes responsibility for which sites to block. I wouldn't be happy as an ISP to take ownership, because I might be sued for wrongful blocking. I wouldn't be happy for rights holders to decide which sites are blocked. So it has to be a competent person like a judge, which introduces a whole new set of costs and issues."

The government is considering creating a third party to decide on such blocking. In March, it met ISPs and other interested parties to discuss creating an IWF-style organisation as a middleman between ISPs and rights holders, creating and curating a blocklist that ISPs would use to block copyright infringing websites.

Culture Secretary Jeremy Hunt has also asked OFCOM to review whether the site blocking measures outlined in the Digital Economy Act are realistic and practical. "I have no problem with the principle of blocking access to websites used exclusively for facilitating illegal download of content," Hunt said.

Not everybody is convinced that blocking copyright infringers is a good idea. Claims of copyright infringement have been used by the Church of Scientology to silence criticism, and by Amazon to justify booting WikiLeaks from its cloud computing servers, while the Recording Industry Association of America famously sued dead people and pensioners who didn't own computers in its crackdown on music file sharing. Who decides whether claims of infringement have merit?

As Peter Bradwell puts it: "We are concerned about extra-judicial censorship. On what grounds will these decisions be made? With what oversight? It's difficult to see how a working group featuring ISPs and rights holders can answer these questions."

Rather than secret lists, Bradwell predicts that: "Legitimate sites will inevitably be either placed on the list or caught accidentally." The ORG believes that the only effective and transparent way to deal with allegedly infringing content is to take the material off the web altogether. So is the ORG telling Ed Vaizey that?

"[In April], the working group met again without any civil society groups involved," Bradwell says. "We have requested that as well as the 'consumer representative' groups [Vaizey] mentions, he meets with rights groups concerned about these proposals. As well as the Open Rights Group, we suggested Index on Censorship, Global Partners, Consumer Focus and Article 19."

So far those suggestions haven't been embraced. "It's frustrating to continually have to make the case that these are broad public interest issues that can't be answered by a narrow group of stakeholders," Bradwell says. "Designing policy for such a group has only brought us bad policy, whether it's the cripplingly poor Digital Economy Act or the secretly negotiated international trade agreement ACTA."

Slippery slopes

The key argument against ISPs shaping what we see is that it's a slippery slope that leads inevitably to oppressive censorship - but the introduction of Cleanfeed hasn't infringed everyday users' activities, mobile phone networks' smut filters have no obvious downside apart from the odd wrongly flagged site, and the Digital Economy Act seems fairly toothless so far.

Are we worrying about nothing? "The slippery slope argument is one of the arguments," Bradwell says. "The force of that argument comes from a lack of clarity around a question that sits at the heart of this debate: who should decide what you are allowed to look at? We don't believe it's acceptable for private arrangements that bypass proper accountability and oversight, to have jurisdiction over your attention."

BT agrees. "Other than for the very particular and most heinous issue of child abuse images - on which BT, like most other ISPs, works with the IWF to prevent inadvertent access by its users - it isn't for ISPs to determine the rights or wrongs of sites related to other issues," Jarvis explains. "It's for the government and parliament to decide policy on site blocking, and in doing so they must consider the practicalities of implementation and the impact on the internet and its users."

We don't hold BT responsible for the things people say using its phone lines, we don't hold Royal Mail responsible for the contents of the letters it carries and, with a few exceptions, we don't hold ISPs responsible for the data they transmit. If that changes, are we losing something important?

"There is an argument that the previous decade will be remembered as a time of wild internet freedom, and that the future of the internet will be more restricted and more closely monitored," Bradwell says.

"The platforms and services [we use] are private organisations, whether they are ISPs or platforms like Twitter or Facebook." The internet is often compared to the Old 'Wild' West, but of course even the Old West was tamed - and the internet will be too.

The concern is that in their efforts to tame the net, politicians and private organisations could damage it. Calls to regulate our 21st century technology raise a first-century question: who watches the watchmen?

Twitter's immediacy and ability to put people in direct contact make it a powerful tool, but there's much more to it than simple status updates, retweets and replies.

Here are 15 Twitter tips to help you to get more from your account.

1. Run a Twitter search

Browse to http://search.twitter.com and enter your keywords in the search bar. You can include Twitter usernames beginning with '@', or hash tags. Click 'Search'.

The results are sorted by time of posting, with the most recent first. You can filter by language and translate tweets into English.

2. Advanced search

A simple search may be enough for most occasions, but sometimes you need to dig a bit deeper to get high quality results that are relevant to you.

Follow the link marked 'Advanced search' and you can specify the location of the tweets returned and a date range. You can also set the attitude of the tweets you're looking for (whether they seem generally positive or negative), and specify the author by Twitter username and any recipient.

3. Back up tweets

If you've been using Twitter for some time, you may be surprised by the number of tweets you've accumulated. You may well find that you've posted enough messages to fill a novel or two.

Backing up your tweets is a sensible precaution to take so you have a local copy in case anything goes wrong. Twitter Backup is a Java program that downloads all your existing tweets to an XML file. Just enter your username and password, then provide a filename for the results.

You'll need to log into Twitter in your browser and authorise the application, which includes obtaining an authorisation code to paste into Twitter Backup. The backup is stored on your PC.

4. Online backup

If you'd rather entrust your tweets to a cloud based service, try Tweet Backup. It's an online service that you can use to back up your tweets on a daily basis.

You need to register using your Twitter credentials via OAuth. You also need to supply an email address for contact purposes.

Once logged in, go to the 'View posts' tab to see your 50 most recent tweets. Choose 'Export' and select a file format to download your most recent backup file. You can download your tweets in plain text, HTML or RSS format.

5. Send a gift

Do you have an online friend who you'd like to send a gift? Perhaps you have a demo or portfolio that you'd like a potential client to see. It's quite common to need to send or receive items at a time when either party might be a little concerned about revealing their full contact details.

Send Social acts as a trusted go-between, arranging to courier your items without sharing addresses. You can request a shipment despite only knowing your contact's email address or Twitter handle. Send Social contacts them and arranges delivery via its courier partner.

6. Share from Chrome

Twitter is great for sharing things that you've found online, but copying a URL, shortening and pasting it into a tweet can be a clumsy affair. Even if you have a URL shortener built into your Twitter client, you still have to copy and paste the full URL of anything you want to share.

TweetRight is a Chrome extension that makes it easy to send links to Twitter. Right-click the item, choose 'Tweetright' and then click 'Post link to Twitter'.

7. Try Echofon for Firefox

Echofon is a Twitter client that works directly inside Firefox. Once you've installed it, you'll see an Echofon icon in the status bar of Firefox. Double-click it to open your Twitter program.

It will appear on top of the web page that you're viewing. As tweets appear, you'll be updated with a popup message showing their number and a brief preview. Echofon is also available as an iPhone client, and standalone client for OS X.

8. Find a lost pet

It's distressing when a pet goes missing, but the people at DogLost will do all they can to help you find an errant animal. Register with the site and provide a description of the missing animal, including pictures, and Dog Lost will publicise it on this site and via Twitter.

Follow @DoglostUK for updates or check the site for a list of found pets to try and match them with a missing animal. It's a simple idea, but very effective.

9. Examine hash tags

Find out the meaning of popular hash tags by visiting www.whatthetrend.com. You can choose trending topics, or search for a term. To learn more about a tag, try the Archivist.

Enter your search term and click 'Start analysis' to see key statistics on the tag's use, including popularity over time and top users tweeting the term. You can check recent tweets too. Summarizr searches the Eduserv archive to provide statistics on a tag or user. You can see top conversations including it and the term's geographical distribution.

10. Simplify the interface

Dabr is an alternative web frontend to Twitter.com that's been optimised for mobile use. It's not as pretty as the main Twitter site, but it's quick and efficient.

It offers many of the functions that some third party clients provide and many users on laptops and desktop PCs opt to use Dabr because of its speed and ease of use.

Browse to the site and log in with your Twitter credentials. Icons next to each tweet enable you to quickly reply, retweet, mark as a favourite or direct message the user. TwitPics appear as thumbnails in the timeline.

11. Predict followers

Want to find out how many followers you're likely to pick up by next month? Twitter Counter analyses your account and provides the number of followers over time plotted on a graph.

It uses this information to extrapolate your likely follower growth in future. You can also find statistics like your current ranking on twitter according to follower numbers and compare this to the most popular users on the service.

You can also enter a friend's username and compare your progress, checking follower numbers and number of updates.

12. Tweet your blog posts

If you have a blog, it's a good idea to let people on Twitter know you've posted an update. You can tweet a simple link, but doing so manually can be a hassle.

Twitter Feed lets you automate the process by linking your blog's RSS feed to your Twitter account. You can sign in using OpenID and link Twitter to your blog. You can check for updates at hourly or daily intervals, and include your blog post title in the tweet.

13. Find more stats

Continuing the theme of Twitter analysis, Twitalyzer provides a different set of statistics to those offered by Twitter Counter. Browse to the site and enter a username to analyse it. This can take a few minutes.

Results are presented in five areas: Influence, Signal, Generosity, Velocity and Clout. Signal is the proportion of tweets that contain information, Generosity is how willing the user is to retweet. Velocity is how regularly tweets are made, and Clout is how often the user is referenced by others. Influence is a combination of these scores.

14. Find out who's unfollowed you

Who followed you initially and sneaked off when you followed back? Friend or Follow helps you find the answer.

Go to the site and enter your username. Friend or Follow analyses your account and presents three lists: people you're following but aren't following you back; people who follow you who you aren't following back and people you're following who are following you.

15. Schedule tweets

It can be handy to set up tweets in advance. The easiest service to use for this is SocialOomph, because you don't need to leave your PC running for the scheduled updates to show.

Sign up for an account and then enter your Twitter account details, authorising via OAuth. You can now select the account you want to use and set up a message.