PlayStation Underground Holiday 2004 Demo Disc

Sometime in November 2004, SCE released their PlayStation Underground Holiday 2004 Demo Disc, which included demos for Ratchet & Clank: Up Your Arsenal, Jak 3, ATV Offroad Fury 3, Star Wars Battlefront, Ace Combat 5, Crash Twinsanity, Tak 2: The Staff of Dreams, The Incredibles, Viewtiful Joe 2 and Spyro: A Hero's Tail, and actually was rated RP-T, not RP-M.

However, the disc contained a fatal flaw that would have serious consequences for those who played the Viewtiful Joe 2 demo...

What happened?
In November 2004, members of PlayStation Underground received a demo disc for 10 games, including Viewtiful Joe 2, that would arrive on December 7th. However, there was a major game-breaking glitch in the demo of Viewtiful Joe 2 that would erase the formatting in any memory cards inserted into the system if you completed the first part of the demo. Sony warned PSU members not to play the demo with memory cards inserted. PSU members soon learned there was no turning back, especially owners of Grand Theft Auto: San Andreas, as the game took a minimum of 40 hours to complete or even worse in very unforgiving games such as Midnight Club 3: DUB Edition, TOCA: Race Driver 3, World Racing 2 or even Richard Burns Rally only to find their save data gone.

Impact
As a result, many people wrote complaints to Sony, which this event caused them to send a free game (full versions by the way) to each and every person who complained as compensation for losing all their save data.

Warning
If you're going to play the demo of Viewtiful Joe 2, make sure you remove all memory cards inserted into the system unless you're looking to delete everything on the card anyway.