Theft: Ability to steal items, ships, vehicles, weapons, datacards, etc., from other players. Also used to determine the likelihood that a lock is successfully installed or broken.
I've been looking around on the forums, and I can't seem to figure out the status on Theft. It seems like making locks is mostly working (moving while installing?), and breaking locks isn't released yet. I saw something about the conceptual part of stealing items, ship, and vehicles already set. If someone could clarify this for me, or direct me to the thread(s) that have at least some of the information, that would be great.
Both making and breaking locks is implemented; to break locks you need a lockbreaker item.
Otherwise, theft cannot currently be used to steal items. The only way to do so is to scam traders by arranging a trade and persuading them to send first to you, then not sending back your half. Common practice, although frowned upon by the trading community. The theft skill itself is not currently implemented for anything like this.
Items can also be 'stolen' although it requires no use of the skill. Just pick up an item you see on the ground and take it with you - unlike any other entities, items can be used without needing ownership.