Re: AdBlocker / NoScript
NoScript is very effective in blocking this sort of thing, but it does break a lot of things in the process. And as Charles 9 says, AdBlock and similar tools are only effective against known ad networks, although often those are the networks being abused.
Ultimately the problem is that ads are what makes the web go round. If everybody blocked ads then a lot of sites would become uneconomical to run (there are of course other ways of displaying ads other than using an ad network).