Yeah, some guy sat down with $8000 a little while ago at my pokerchamps limit game... On no-it games (atleast here) they do have a max, as I would imagine people could bully the pot without one. But in a Limit game it really doesnt matter.
We did all make fun of him thought
EDIT: oh by the way, for those of you who don't know, i play microlimit at a limit .02/.04 table!