A patent filed by Sony suggests that the company will prevent the PS4 from playing second hand game discs using an RFID tag.
The patent would allow the console to check if that game had already been linked to another console or account - the kicker being, it wouldn't even need to be online to make the check.
There's no saying that Sony would definitely use this RFID check system on all PS4 games, but it does give it the option to essentially destroy the second-hand game market.
Gaming the system
As Kotaku points out, it's more likely that Sony will use the tech to restrict some game features, rather than completely blocking the entire game.
For example, the RFID plan could spell the end of the 'online pass' which allows gamers to play online for a fee; this fee would be built into the game but only the original buyer would be able to play online.
While Sony Computer Entertainment America has spoken out against blocking used games in the past, this patent came from Sony Computer Entertainment HQ in Tokyo, which may take a different view.
Then again, perhaps Sony has no plans to implement the RFID tagging check at all and will just hang onto this patent to stop others using it.
One thing we do expect is to find out by the end of the year - while Microsoft already seems likely to announce the Xbox 720 at E3 2013, we're also expecting a new Playstation to surface at some point too.