Yeah, the big networks such as Google AdSense are easily one of the easiest attack vectors for viruses and such and we would never annoy you with invasive, crappy ads nor ever forcing you to see them. Project Wonderful did a pretty good job at not doing that.
On that, once it disappears, you might be able to give me a good price to put your own ads manually in in its place, that'd be nice.
I actually have a good recommendation. If you really wanted/needed to put up ads, add AdSense ads, (jeez so many "ad"s), but have them disabled by default. Then, the user could opt-in to see them (which I would do, I really don't mind ads of any caliber, as long as they stay in their little box and aren't too NSFW or whatever). Disable them even for guests, if you really felt it was necessary.