If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
My usual browsers are pretty much locked down all the time, but I dug out IE and looked at some LW pages. Didn't see any ads, video or not.
I would suspect malware, but it's also possible that other browser tabs (e.g. Facebook) are playing games...
P.S. Oh, a plug-in I have says there are three "requests" on this page from SpecificMedia (http://specificmedia.com/) and it does seem to specialize in video advertising.
I just loaded http://lesswrong.com/ in both my Iceweasel and Chromium (Debian testing), and C-u, C-f 'suite', 'specific' - I see nothing? Nothing in curl either.