Concur with tightening TorBlock. if we can clamp down on open proxies identified by other feeds and listing sites, I'd be fine with that as well.
Note that this is not just just because of one known prolific sock user, but because of the overall net benefit to the editing community if sock-users have a higher hurdle to cross, to edit via a "random unconnected IP".
(Adding some side information: experience on enwiki suggests that IP block exemption works effectively; we have had a reassonable number of requests, and because each account needs IPBE individually, even if a problem user does apply for IPBE and is granted it, it doesn't "break the bank"; it's still hard to set up a nest of socks that way.)
FT2