I disagree. They have a bad enough reputation as it is. If firewalls start seeing ad servers as potential threats there goes their business model. It's distinctly important for them to be able to block things like this. It's their whole livelihood. (I used to work for a banner advertiser, so I know first hand).
And yes, you may refer to me as Satan now. Yes, I was also one of the first big spammers (I caught a Macintosh on fire making into a high velocity mail server running Linux). And yah, my team may have invented the concept of delayed popups and pop-unders. Oh yah, and viral marketing to change people's homepages using trojaned movies? That might have been my team too. I'm a bad bad man - or was anyway. You may now claim that I have contributed to the worst things on the Internet.
And now for my next trick I shall break the same origin policy and pave the way for ultra complex XSS malware....
- RSnake
Gotta love it.
http://ha.ckers.org