The ability to steal really shouldn't be part of your RPG criteria.
why not?
Because saying something is not an mmorpg because it doesn't have theft isn't really right.
However, I think what you meant is "if I do this action, will it have a consequence?". With MMORPGs, this is probably more true than any single-player RPG. Except instead of pissing off an NPC, you're pissing off a PC.
And yes, World of Warcraft provides the ability to steal.