I just started throwing this page together, so bare with me. There is no federal law regarding spam. When spammers quote alleged laws they are quoting bills that never made it past Congress.
Spammers use the resources of ISPs and mail servers without consent.
Spammers almost always try to disguise their identities by faking the headers in an email. What you can do Make sure you understand what UCE is, and be certain of each e-mail message you believe to be spam. I personally subsribe to the SpamCop service. Protect your e-mail addresses. If you have a web site and you post your email address you WILL get spam.