Moderator, WTF is pubads.g.doubleclick....???

I get this crap almost every day that I browse this forum. After looking at a few threads, I hit the back button and nothing happens. Then I look at the recent history list and it is full from top to botom with this address repeated over and over:

http://pubads.g.doubleclick.net/gampad

I don't know where this comes from, but it really PISSES ME OFF!!!!!

I never get this BS on any other web site.

I have to close IE and re-open it to get back to the forum.