as far as i can recall, only 360 users who have uploaded game saves before sites implimented an encryption alogorythm to protect uploaders console ID's have been revoked. there are way more than 400+ 360 users that have uploaded gamesaves to various sites.
i dont think it has to do with pissing off M$, i havnent heard of to many cases where someone has been revoked out of no where, most people dont even know what it means. once they are told what it means, its usually, "yep, i think i just got myself revoked"
i am an owner of 2 revoked consoles, one of which has never seen xbox live, so this list is real as any saves or profiles created on this 360 that has never seen live will not load on any other system, i believe this list is also stored in our profile data as i also cant load a profile that wasnt created on this system either, even though it has never seen live.
dont get to worried if you have never uploaded a game save to a web site, this seems to be the only way to get your console ID added to this list.
if you lagged someone out in halo 3, what kind of punishment would the revoked list be, they are banning you from matching making as punishment, not the revoked list