I should also say that at least I don't try to run any kind of scam with my aliases.
On a Battletech board I check out everyonce in a while, they just banned a guy who had about 10 different aliases.
The thing is though that he played out this elaborate soap opera amoung the different aliases that included one of them dieing in a car wreck, and an other being injured in same wreck, This played greatly on the emotions of the real people who hung out on the board, and they sent flowers and get well cards and everything. People started to get suspicious when some of the guys wanted to road-trip to the funeral, but another of the aliases posted that it was closed to only family. Then, they decided to visit the one who was only injured in the wreck in the hospital, but it was posted that she could only be visited by family.
Finaly, the admin started cross-referenceing IP's on a hunch, and the ruse was discovered, resulting in a life-time ban.