Rogue Pickpocket Skill (Looking for definitive ruling)

[fastboy21]

I almost didn't want to post this question because it has the ability to turn into a whole debate (that has been had before, I'm sure) over pickpocket skill for rogues.

Is the use of this ability ever a violation of GM policies? I'm not very interested in whether folks think it is wrong or not. I'm really just looking for a statement from a player who knows the rule from a past GM post (link would be good if you have it) or a statement from a guide.

Example, is it a punishable offense to pickpocket a mob that someone else is killing? is it a punishable offense to pickpocket without group mates consent?

These are obviously not good things to do, but i'm really just interested in the rules side of the action.