I ask TradeHill to totally deactivate referral codes for now, since this is an incentive to spam and scam. And you won't be able to manually deactivate every infringing account one by one, it isn't worth the pain. Let the situation calm down, until the referral codes are used for fair uses.

ps: got 2 spams:

"Mt Gox has been hacked"
?r=TH-R15683
Received: from goemitar by bonecrusher.gulfsouthmedia.com (envelope-from <goemitar@bonecrusher.gulfsouthmedia.com>)
Last remote: 209.223.236.66 (bonecrusher.gulfsouthmedia.com)
http://network-tools.com/default.asp?prog=express&host=209.223.236.66

"Important message to Bitcoin traders!"
?r=TH-R15977
Received: from server ([46.5.146.44]) by home  [s15389739.onlinehome-server.info]
Last remote: 87.106.62.244 (s15389739.onlinehome-server.info)
http://network-tools.com/default.asp?prog=express&host=87.106.62.244

Enjoy your spam reports.