With their 3.5 update for the Playstation 3 Sony is trying to stop unlicensed third-party controllers. Sony writes that they can be dangerous, explode and ruin your machine. Here's what they write over on Playstation.com:
"Counterfeit PlayStation 3 Wireless Controllers, which are practically identical in appearance to genuine PlayStation 3 Wireless Controllers, have been discovered in the market. SCEA advises consumers to be cautious when buying PlayStation 3 Wireless Controllers from uncertain sources as the quality, reliability and safety of counterfeit products is uncertain, and in some cases, may be dangerous.
"It is possible that some counterfeit product may ignite or explode, resulting in injury or damage to the user, your PlayStation 3 computer entertainment system, or other property. Moreover, SCEA does not support continued functionality of counterfeit or unlicensed controllers in system software updates and these devices may cease to function in the future because of system software updates."