This page talks about how we can use our computers to evaluate the material we find on the Internet, not least by trying to discover who placed it there. Follow this link for more general hints about browsers and email.

What the Internet knows about you

Bear in mind that reading Internet pages is not like reading a newspaper. Every computer that connects to the Internet has an identifying address, called its IP number. That is passed to the sites you visit.

If you connect from your office, and you have a permanent connection to the Internet, you will have a "permanent IP number", which means the actual physical ownership and address of your computer can be known by those you visit. If you connect from your own computer, via a "dial-up" connection using an Internet Service Provider like Freeserve, you are given a temporary IP number for the duration of your session.

This protects your privacy to a certain extent, but it does not protect criminal activity. The providers keep logs of those using their services, and they can be searched when there are crimes.

None of which should worry us unduly if we are pursuing lawful activities. It does mean, however, that what we say and do on the Internet can have consequences in our real lives.

Anonymity on the Internet

There is a strong tradition of anonymity on the Internet. People writing in the newsgroups habitually use pseudonyms. If you are trawling for information there, it may be sensible to do the same or use a hotmail-style email address that is not easily traceable back to you.

If you want to do your web research without leaving a trail, you can do so by typing in your web addresses on a page called the Proxify. To learn more about this vast and controversial subject, try, where you can also click a link to be told exactly what type of computer and browser you are using and who your Internet provider is. If you connect from an office computer, it will probably be able to tell you what you can see from the window.

Finding out about web pages

But while they are finding out about you, you can find out a little about them. Mostly, we have to rely on contextual clues to a page's credibility, just as we do with printed documents. Here is a good paper on evaluating Internet pages, by Professor Robert Harris of the University of California.

It would be nice to know when a page was written, but that is more difficult to determine than it should be. If the server hosting the page has its clock set to real time (and they often don't), you can tell when the page was last updated by keying the following formula into the address box of your browser, without the quote marks: "javascript:alert(document.lastModified)". Unfortunately, many pages these days are updated automatically, or "created" when you link to them: you can't find out when they were actually written.

You may want to know who owns a particular domain name. One method is to go to one of the administrative bodies. For .com and other American/global addresses, go to Internic. For and other British addresses, go to Nominet UK. In both cases you are looking for a button that says "whois". Shortcut: most domain name sellers will offer the necessary whois search as part of the process of selling you new domain names. I use one called DomainTools.


No page on Internet sleuthing would be complete without a reference to viruses. Most "viruses" are actually hoaxes. Please don't pass on email "virus warnings": if the virus was real, it would already have reached everyone on your mailing list. If you are worried, go to a reliable virus encyclopaedia, for instance the one at Symantec.