Which is why most people are "dumping" the files off on massive hosting sites like rapidshare.com and megaupload.com and splitting the files in rar's. Then they password protect them with the name of the site who upped them which are usually only message boards. This process is called DDL or direct download linking. It's quite common and more often then none- safer on both sides.
If you own a playstation game and you port it to the PSP that is not illegal. If someone you know ports their copy of a Playstation game to your PSP that is not illegal. If you willfully download with the intent to distribute, redistribute, profit, or contain for a period of more than 18 hours(It's not 24 which is a common misconception) then you are by law "pirating."
Piracy is a punishable offense in America by up to but no further than - 4,000USD and 14 days imprisonment. Anything filed by the company whose proceeds you have diminished, deprived them of, or delinquently neglected will then be added to your existing charges. And you may or may not have to pay for the fees you'll incur if they win. Most of the time the company will let you go, or settle out for a small payment no less than 10,000USD.
Be smart, if you pirate- don't say it out loud unless you're on a message board.
The FBI, CIA, and local PD do not care.
The RIAA, The MPAA, THE ESA, and the ACR do. And they will sue your ass.