I noticed an SE page was communicating with a load of tracking sites, as in, a load. I did some experiments. I am using Chrome, latest, on Windows 7. I have been using Ghostery and adblock since ...
[EDIT] I found the piece of adware - turns out it was made in some automation software and was designed too simply to be detected by Spybot et al. I'll mark the best answer below, but it didn't ...