Tag Archives: History sniffing

Internet Privacy is Still A Problem

I’ve been nagging you and nagging you some more about the Internet and how it isn’t the safest place in the universe if you value your privacy. Many of you insist on putting private thoughts and experiences on MySpace and Facebook and then are horrified when there is some negative blowback in your lives, like from a boss or friend or family member reading some stuff you wish they hadn’t.

Well, it gets worse.  Dozens of websites have been secretly harvesting lists of places their users previously visited online.  That includes everything from news articles to bank sites to pornography.

The information, according to the Associated Press, is valuable for con artists to learn more about their targets and send them personalized attacks.  It also allows e-commerce companies to adjust ads or prices, for instance, if the site knows you’ve just come from a competitor who is offering a lower price.

This technique is called “history sniffing,” and is a result of the way browsers interact with websites and record where they’ve been.  It only takes a few lines of programming code to pull it off.

Current versions of Firefox and Internet Explorer browsers still allow this, as do older versions of Chrome and Safari. 

Researchers at the University of California, San Diego found 46 sites, ranging from smutty to staid, that tried to pry loose their visitors browsing histories using this technique.  Nearly half of the 46 sites, including financial research site Morningstar.com and news site Newsmax.com used an ad-targeting company Interclick which says its code was responsible for the tracking.

Again, according to the Associated Press, the source for this whole announcement, Morningstar, said it ended its relationship with Interclick when it found out about the program and Newsmax said it didn’t know history sniffing had been used on its users until the AP called.

Internet companies are obsessed with tracking users’ behavior so they can target their ads better.  The Federal Trade Commission is proposing rules that would limit an advertiser’s ability to track Internet users to show them advertisements.

History sniffing is essentially a side-by-side comparison of Web pages you’ve already visited with Web pages that a particular site wants to see if you’ve visited.  If there is a match, users would never know but the site administrators would learn a lot about you.

For instance, according to AP, a popular porn site was checking its visitors’ history to see if they’d visited 23 other pornography sites, and the code used on the Morningstar and Newsmax.com sites looked for matches against 48 specific Web pages, all related to Ford automobiles.

Sites can carry on this kind of inspection at the rate of 20,000 Internet addresses per second.

Remember all this when you next sign on to the Net.