Not sure if you've used google to advertise with before but they will work out that this user is clicking maliciously and discard them. The whole point is they won't get revenue from this unless you visit very few sites.
So does that make it better or worse than just blocking adds?
Worse, as ad networks can--and do--block publishers for click fraud.
well they will be able to identify that the user is responsible, not the host. hopefully
How?
Same way they do now. They don't publicize the algorithms i believe
http://www.google.com/ads/adtrafficquality/invalid-click-pro...
If you don't like sites with annoying adds why send them revenue from click throughs? There are also a lot of hard working companies out there that would rather not pay $0.25 every time some ass hole with a browser extension visits a page.
edit:toned down.