The file swapping heyday may be coming to a close. From my perspective, the best rule of thumb: if it's questionable ("grey area") don't do it.
An MTV.com article reports that the RIAA has obtained over 800 subpoenas [in June], with roughly 75 new subpoenas being approved each day. The list includes users who have shared as little as eight songs.
Congress proposed a new bill that would land a person in prison for five years and impose a fine of $250,000 for uploading a single file to peer-to-peer networks like KaZaA. The bill was introduced by Reps. John Conyers Jr. (D-Mich.) and Howard Berman (D-Calif.). As if the RIAA's attacks on file-swappers weren't enough.
Another bill was proposed last year which would protect copyright holders from liability if they impaired or disrupted the unauthorized distribution of their content on P2P networks. That bill is still being debated.
New Bill Seeks Prison Time for File Swappers (Internet.com), Congress mulls prison terms for KaZaA users (Register.com)
These references were found at nembis.com
Also, in Wired: "Spanish Firms Target File Traders"
Photo source: CNN, "File-swapping 'Madster' must track songs"