By DAVID KESMODEL THE WALL STREET JOURNAL ONLINE
Earlier this summer, Uno Bloom, a songwriter in Brentwood, Tenn., noticed that his home computer appeared to be slowing down. He searched the files on his hard drive in an effort to uncover clutter, and found dozens of Internet cookies labeled "2o7.net."
He started monitoring his cookies -- small tracking files that are automatically downloaded when users visit Web sites -- and realized some of the suspicious files were coming from Ameritrade.com, where he trades stocks. He did an Internet search for "2o7," and learned in a computer forum that cookies bearing the name were maintained by Omniture Inc., a Web analytics firm. Omniture helps its roster of high-profile clients, including Ameritrade Inc., eBay Inc., Wal-Mart Stores Inc. and Expedia Inc., study how people use their Web sites.
Mr. Bloom is one of a number of computer users who grew suspicious when they discovered the files on their computers, either through manual searches or by running antispyware programs that flagged
2o7.net for potential deletion. Adding to their concerns: when users plugged
The controversy over the 2o7.net cookies highlights the tension that exists between marketing companies like Omniture and Web users who are increasingly aware of, and adverse to, files that are automatically placed on their computers when they surf the Internet. At a time when PCs are under assault by viruses and other nefarious software like never before, users are employing a range of software tools and tactics to protect themselves. Many users don't distinguish between cookies, which are small bits of text commonly used by Web sites to identify users, and malicious software that can steal personal information or change PC settings. That has put marketers on the defensive, as they try to get users to spare cookies when wiping computers clean of potential threats.