/borg-ing, as well as any other action that globally affects a user (including things like account deletion), ought to be audited and the actions noted in a public place. If the actions was inappropriate this is the only way for it to be generally known that it happened as well as who did it so there is some measure of accountability.
in reply to Reputation and Accountability
At the very least, if the records are deemed to be transient (lasting, for example, only as long as the sanction is in place), the user who was affected should be /msg'd and any transient tracking nodes (such as Borg's Belly) should note who did it and when. Borging warrants an automatic message in the chatterbox as well, I'd say.
Nothing wrong with drastic actions. It's just the anonymous drastic actions that are worrisome.