Yes, they use http://www.mediawiki.org/wiki/Extension:TorBlock. There is a client-side bot that blocks open proxies as well.

Wikipedia says:
"Domain tasting should not be confused with domain kiting, which is the process of deleting a domain name during the five-day grace period and immediately re-registering it for another five-day period. This process is repeated any number of times with the end result of having the domain registered without ever actually paying for it."

So I guess that's dead, too?

Also, I believe that tasting was supposed to allow the registrar to recover money in the event of a credit card charge-back or non-paying customer.