Turns out even Smith was surprised by what we would discover. Smith was tutoring me on what you might call online countersurveillance, giving me a lesson in how to watch the watchers on the Web. We were in his of ce overlooking downtown Boston. Our laptops were on. On screen, we were looking at a popular porn site called iFriends.
Web bugs are the latest innovation in the art of monitoring people moving through websites.
They are computer code, nearly identical in structure to the code for a picture or a banner ad. That describes an image one pixel wide and one pixel high, with no border. That clued him in to the fact that DoubleClick Inc., the most successful Internet advertising agency, was collecting information about our visit to a porn-related site. DoubleClick is an online advertising agency that buys and places banner-ad space for its clients. But it adds another layer of service, too it keeps track of who views and clicks on those banners, and now, with Web bugs, it can track people on pages without banner ads.