Something you should add about those script blockers is they don't work as well as they could on IE/Chrome. Firefox has the "parts" in place to allow, NoScript for example, to prevent the scripts/etc from even being downloaded. Chrome, as far as I know, still doesn't have them. Hence why you don't see NoScript on Chrome.

Although after looking, it looks like some addon makers have found workarounds for near complete or complete functionality on Chrome.