The Insider News

Ars Technica[^]:

Using graphics to collect metrics is an old hack, going back to the "sprites" used on many early personal Web pages to track page views. Web request based tracking is also heavily used by both legitimate large-scale e-mailers and spam factories to collect information such as when and where e-mails are opened, and to test the "hit rate" for various subject lines and offer teases. But ContactMonkey gets even more personal about it, because it identifies each recipient explicitly, and reports back directly on them. It's a technique akin to those used by some "spear-phishing" attacks to inject code into e-mails—no, it doesn't execute code on the client. But it does create a way to collect information that might be useful for stalking someone.