Re: arms race
There are ways to make ads unblockable.
Text ads get baked inline with the article. The only way to block the ad would be to block the article, making it a pyrrhic victory and defeating the purpose of the ad blocker (you want to block just the ad, not the whole page).
Graphical ads can be given a hash name so that it's different every time, making blacklist useless from the whack-an-ad shenanigans. Furthermore, ads can be programmatically baked into images genuinely to do with the article the way product placement and ads are now baked into TV shows so that you can't skip them without skipping the program.
The nuclear option would be a clickwall, and the loading of ads (especially in-house ads) can be detected by the server without any scripting, especially if the filenames are hashed (and thus tagged per session).
Yes, I know the nuclear countermeasure would be to abandon Facebook, but for many it's the only way to keep up with remote family (because where they live Internet, including e-mail, is a premium while Facebook is gratis) or other reasons that make ignoring Facebook "Walking on the Sun."