As I see it, the deletion of the entire content of a node doesn't happen too much. In case it does, it's most likely done by a user that's quite new to this site. The node will be massively downvoted and -most likely- there will be some comment on it. This will show the new user that, instead of deleting it, he can better use <strike> tags and/or an Update paragraph.

Of course a style of American law enforcement could be implemented, where the offender will (be locked up with a tripple life sentence and) never ever get a chance to learn from his mistakes and try again, but I'd favor the more liberal approach to it of letting it slide. The comments and downvotes should tell the abuser enough. If it doesn't help, just ignore the user :)