identity is not property - so how can you "steal" it?

 another poor metaphor (as with security theater, which isn't even poor stand-up), identity theft.

as with music piracy (aka p2p file sharing), you copy, you don't  take. but in this case, the metaphor of theft is even less apt, as identity has some deep roots (e.g. biometric attributes) and some more shallow (notarised documents like birth cerrtificates, passports) and some social contextual attributes (people vouch for you)

mistaken idenity (the mcguffin of many a fine play, film, book, but perhaps not song) is apt

but identity theft just isn't.