Anonymity is also reputed to be valuable for whistle-blowers, although the only incidents I know of its use for this purpose were the posting of internal Church of Scientology documents by its critics. None of this is prevented by the Anti-slamming Act, but legislators need to remain sensitive to the value of anonymity. If UCE or any other email abuse pushes forward a drive to shut down anonymous remailers, many innocent people will suffer. This was precisely the effect of a lawsuit by the Church of Scientology against a popular remailer in Finland that was the conduit for unauthorized news postings containing Church documents. The administrator of the remailer was forced in 1996 by a court to reveal the identity of the person making the postings, and thereupon shut down the remailer in disgust.
Few spammers are really anonymous, even if they use fake email addresses.
To buy their services you need their address, phone number, or Web URL, all of which would permit them to be traced if Congress passed a law with teeth. The one thin benefit of prohibiting fake email addresses is that system administrators and users can filter out email from known spammers. But the value of this practice would be greatly reduced by the bill, ironically, because it actually encourages spammers to change email accounts frequently. The travesty of the act is that it makes the first email from any organization legal. Meanwhile, to shut off mail from any spamming account, you have to reply to the message and ask to be removed from their list.