AOL, Microsoft, Earthlink and Yahoo are suing hundreds of marketing companies and individuals for sending deceptive spam using a new federal law called the CAN-SPAM Act, which prohibits such activities.

Online marketers who hide their identities and distribute emails advertising get-rich-quick schemes and pornography are the subjects of a coordinated legal effort and the email providers claim to have the offenders identities.

Providing false return addresses, routing email traffic through proxy computers and including advertising that is of a deceptive nature are just some of the many claims that the lawsuits contain.
Source

Know what annoys me worse than commercial spam? Those stupid people who always reply to EVERYONE that "x" message was sent to.

Example: I got a stupid email "FW: Think about this"
I would normally simply delete it and block the person who sent it to me, except I also got 20 emails titled "Re: FW: Think about this"
Seriously, I don't care what you think about the stupid FW, did you actually think I was gonna read it?

No, what I hate is working for a webhost who is hosting a domain that people are spoofing headers from...

"I keep getting spam messages from this user saying blah blah blah"

"The headers do not originate from our servers, please browse the headers and email the users ISP."