Interesting tidbit on how the FBI tracked down a Russian spammer:
So how did the FBI get its man this time around? By busting the US-based distributor of fake Rolex watches who used Mega-D to send a good chunk of his spam. That led them on a trail that culminated in ePassporte, a money transfer service, and they found Nikolaenka’s name and e-mail addresses attached to his account.
Nikolaenko had made another mistake: the e-mail accounts were Gmail addresses, and it was no trouble at all for the US to get a subpoena, forcing Google to cough up the account information. FBI agents found copies of the botnet software and much else of interest among the e-mails.