Good point about the abuse aspect. I bring to mind the kill-switch ideas for mobile phones and how badly those plans work or are intended to work. Definitely requires some more thought.
However, what may be easier is simply some authentication in place on the wallet that requires a correct passcode before actually sending any coins. As it stands now, it is simply too easy to transfer coins. Break in to the system, and the bank is yours. If there was some sort of authentication on not only accessing the wallet itself, but also the 'send' function, i do believe it would drastically reduce the number of successful thefts.
I believe wallets do have it. They are usually locked (unless minting) and require password to sign the transaction. Though gaining access to victim's computer may allow key logging, especially if it's administrative access.