Protect your privacy while surfing the internet

If you thought staying anonymous online was simply a matter of not using your real name when posting comments, you could be in for a bit of a shock.

Even if every single aspect of your internet persona is completely concocted, your web browser still reveals enough information about your computer to the sites it deals with to enable someone to track it, and therefore you, down.

Unless you’re engaged in something suspect it’s unlikely that anyone gives two hoots about who are and what you’re up to, of course, but there are situations where it pays to pay closer attention to online privacy.

There are people, whistleblowers for example, who might have very good reason to wish to hide their personal information online, while others simply prefer to be in charge of what personal information is shared.

In a moment we’ll explain exactly how you can control what personal information is shared when you use the internet. But first, let’s take a look at exactly what website owners can tell about you and your PC.

What’s shared
If you’re near a computer, open your web browser and open the website Browserspy. Look down the left of the page and you’ll see a long list of categories that shows the information that your computer is providing to the site, and so to any website on the internet that looks for it. Try clicking a few to see what the site knows.

Some of the categories may not mean much but some should be instantly recognisable. The computer that runs the Browserspy site knows what web browser you’re using, for example (click ‘Browser’ to see), along with how much room that browser is taking up on screen. At the bottom you’ll see it can tell which operating system you’re running, too.

Your web browser provides most of this information by design and the idea is that helps improve the way the web works. For instance, knowing that 50 per cent of a site’s visitors have a screen measuring 1,024x768 pixels could be helpful for the people who design that page.

However, this information also has the potential for misuse. Given that many security exploits affect only a specific web browser, knowing which one you’re using could help an attack site target each visitor effectively.

Close to home
It’s important to note that while the information about your computer your web browser gives away to other computers that host websites can be surprising, it doesn’t represent that much of a privacy problem; after all, it’s about your computer’s capabilities, not you.

Some information you inadvertently reveal online, however, can be more revealing.

Click the link on the Browserspy page for ‘Geolocation’ and you’ll see a map that shows the city where you live.

The site isn’t using secret information to arrive at this location, just your IP address (the series of numbers that uniquely identifies your computer on the internet).

Everything with an internet connection has an IP address and some websites make a show of ‘logging’ it whenever you visit, the implication being that since they know the unique online ID of your computer, the owners know who you are, too.

Fortunately, tracing someone from an IP address alone isn’t quite so straightforward as anyone who gets online via an internet service provider (ISP) can only be traced as far as the ISP, and possibly a rough geographic area (which is why Browserspy can only pinpoint your location to the city in which your ISP is based).

Going any further to find your street address requires a court order to compel an ISP to provide the necessary information that links an IP address to a particular customer. Of course, these records will be those of the person who pays the ISP’s bill and not necessarily the person the court order seeks to trace.

Digital footprints
It may not be possible for just anyone to turn an IP address into a street address with an ISP’s help but that’s not to say the information can’t still be used to identify you online.

The problem is that if you’ve used the internet for any length of time, you’ve almost certainly left a trail of digital footprints in the shape of website comments, forum posts, profiles on social-networking sites and so on, and given time these can be pieced together to pin you down.

Armed with an IP address taken from an anonymous comment on a website, for example, it only takes a little detective work to reveal messages posted on other sites from that same address, some of which may have a name or other identifying information attached.

The IP addresses assigned by most ISPs do often change over time, making some links incorrect, but corroborating information can often give the game away.

When the IP address belongs to a business or other organisation, the gig can be up even sooner and there have been numerous cases of sly changes to the online encyclopaedia Wikipedia being traced to the offices of political parties, for example.

In fact doing anything internet-related using an office computer is the quickest way to give up your online anonymity. Many larger businesses maintain logs of the websites that are accessed by its own computers and once an IP address has been tracked back to a business, a date-stamped anonymous message is usually all that’s required to trace its origin.

So, if you’re planning to blow the whistle on your boss’s shady practices, for example, it’s best not do it at work.