Last July, a research team from the University of Washington released an online tool to analyze whether web pages were being altered during the transit from web server to user. On Wednesday, the team released a paper at the Usenix conference analyzing the data collected from the tool. The found, unsurprisingly, that ISPs were indeed injecting ads into web pages viewed by a small number of users. The paper is available at the Usenix site. From PCWorld: "To get their data, the team wrote software that would test whether or not someone visiting a test page on the University of Washington's Web site was viewing HTML that had been altered in transit. In 16 instances ads were injected into the Web page by the visitor's Internet Service provider. The service providers named by the researchers are generally small ISPs such as RedMoon, Mesa Networks and MetroFi, but the paper also named one of the largest ISPs in the U.S., XO Communications, as an ad injector."