I'm not certain how anyone can stop new Troll accounts, the sharing of Troll accounts, or the "new" technique of the ultra-lurk Troll (someone who spawns a lot of accounts, lets them sit for months to "age" and then goes Trolling at a future date) without denying new membership altogether Such a response to Troll-kind would ruin the open forum nature of FR in the first place. It would be letting the Troll-sters win!
Becuase the Trolls covet our freedom and our lively forum, we must be on constant vigil angainst their incursions. That's where the Cult of the Viking Kitties and their untold followers come in. 8^)