Some people collect Trophies because they’re a great way of recording your hard earned achievements, but some PS3 owners don’t agree, and for some reason want to increase their Trophy count without actually playing the game. It’s the equivalent of winning a race when someone else is driving, or taking out a distant target with someone else aiming: essentially, it’s pointless.
Still, that hasn’t stopped some individuals, who appear perfectly happy to use save game hacks and other nefarious ways to get at the silverware they, I assume, wouldn’t normally be skillful enough at the game to get. Like, for example, the Fuel hack below, in which the guy behind the camera simply uses a save game from the internet to boost his Trophy count considerably, getting lots of Trophies in just a few minutes of booting the game up.
As far as I know all Trophies, once synced, are locked to your account with the time and date stamped alongside them, so all Sony need to do is check for Trophies all attained within a reasonable amount of time. If you do this kind of cheap hack on an Xbox 360, your account will be banned but for some reason Sony feel far more reluctant to actually do anything about stopping it on PS3. SOCOM and Call of Duty: Modern Warfare 2 apparently have similar loopholes.