Do you surf the web but wonder how those sites you visit seem to know you? Many sites gather data, such as IP addresses and search parameters, from users who visit the site. Some pages also leave cookies or “spyware” on the user’s computer so that the site can differentiate users and customize content based on surfing interests. In short, many sites build an ever-updating profile of you, from the items you think about buying to the news you prefer reading.

Most websites claim to do this in order to provide the best possible service to their customers. Not everyone likes the idea of being tracked online, though. For example, privacy concerns have been raised about cookies in the past. And in 2006, Microsoft, Yahoo and America Online admitted to giving records of their members’ internet searches to the U.S. Department of Justice when they were subpoenaed during a web filter investigation, despite the fact that more than half of internet users polled said that they are against search engines turning over data to the government (Google fought the subpoena and won a minor victory against the DOJ). Many people didn’t even know that sites collect unique identifiers such as IP addresses.

To combat online snooping, web anonymizers, or anonymous proxies, were developed. These allow the user to surf the web without leaving a personalized trail behind. The anonymizer accesses the internet on behalf of the user and relays the information in a safe, untraceable manner while hiding the user’s personal information from outside sources (acting as a sort of buffer). The need for this sort of tool becomes readily apparent when we think about anonymous whistleblowing or the discussion of taboo topics, or when people in oppressive nations wish to access websites blocked by the party in power. But anonymizers are also popular with many ordinary users who simply don’t want to be tracked. After the 2006 subpoena incident, for example, sites such as Anonymizer.com and FreeHaven.net saw a sharp spike in membership.

Do anonymizers work? Yes, but with limitations. For example, some anonymizers can’t process secure protocols like “https://” because your browser needs to access the site directly for the encryption to work (NEW INFO: anonymizer.com now handles https; thanks to Lance Cottrell for leaving the comment updating our information). Plugins might have problems, as well, and Java and JavaScript might compromise your security and allow identifying information to be accessed if you use the anonymizer as a regular proxy. Also, anonymizers mean that web sites will no longer be personalized to you when you visit them; a shopping site won’t already know what you like to buy when you go there, so you’ll have to start from scratch in filling your shopping cart.

In short, anonymizers aren’t perfect. They’re simply pieces of software that can be circumvented in some cases, and no matter how smart the software “mouse” becomes, someone will probably build a better mousetrap. Still, as long as you don’t expect anonymizers to be ironclad, they can provide a measure of protection from online tracking. Don’t let things like a firewall and anti-spyware protection slide, though; the more security you have in place, the safer you’ll be.

Sources for this article: www.eweek.com, www.searchenginejournal.com, www.anonymizer.com, www.livinginternet.com, www.securiteam.com, www.opennet.net, searchsecurity.techtarget.com