Prevent Multiple account in Vbulletin

[jakemiles]

I want to migrate from phpbb 3 to Vbulletin 3 (i think with this i have no problems) and i wonder if there any strong multiple account prevention like on planetsuzy.org (big forum with 10K viewres)
For exmpl:
Someone will register 10 accounts and prevent posting limit on my forums. I wonder if someone knows is there any good public mod?

[bananalive]

This modification is good: Multiple Account Detection & Prevention