Sony has researched and patented new technology that could be implemented to block used games. As spotted by a NeoGAF user, patent application number 20130007892 for an "Electronic Content Processing System" and "Use Apparatus" would associate individual game discs with matched user accounts.

Games that are discovered to be tied to another user's account could potentially be rejected. The system works, according to the document, by attaching contactless RF "tags" to each game, which can be read without a network connection.

The filing does not mention any specific system for its use. However, past speculation suggested Sony was interested in curbing secondhand sales with the PlayStation 4.

"A game playing system includes a use permission tag provided for use in a game disk for a user of a game, a disk drive, and a reproduction device for reproducing the game," reads a line from the patent's abstract. "The disk drive reads out a disk ID from the game disk. When the game is to be played, the reproduction device conveys the disk ID and a player ID to the use permission tag. The use permission tag stores the terms of use of the game and determines whether a combination of the disk ID and the player ID conveyed from the reproduction device fulfills the terms of use or not."

In the patent filing, Sony said in a content business like the games industry, it is "vital" to redistribute a portion of the proceeds from sales to developers, who do not see a dime from secondhand sales. Sony said though the secondhand market may expose new gamers to a particular title, in the long run, this does not benefit developers.

"In such a scheme where the electronic content is bought and sold in the second-hand markets or the like, the sales proceeds resulting therefrom are not redistributed to the developers," reads a line from the filing. "Also, since the users who have purchased the second-hand items are somehow no longer potential buyers of the content, the developers would lose their profits otherwise gained in the first place."

Sony said this patent would effectively "suppress" the secondhand game market if it ever comes to fruition. This technology would also be applicable to other forms of electronic content, including images and music.

The patent was originally applied for in September and was published today. It does not necessarily indicate that Sony will, in reality, block or in any way prohibit gamers from playing secondhand titles on the PS4 or any other device.

The used-game market has been a contentious issue, with several noted developers making clear their stance against secondhand sales. Those who spoke out against used sales in the past year include Crysis developer Crytek's director of creative development, Rasmus Hojengaard (though he quickly recanted), Battlefield 3 executive producer Patrick Bach, ex-THQ executive Richard Browne, Elite creator David Braben, Volition design director Jameson Durall, and Silicon Knights founder Denis Dyack.

Not all voices are against used games. Saber Interactive CEO Matthew Karch said in February 2012 that blocking used games is unfair. Also during that month, Witcher developer CD Projekt Red's managing director, Adam Badowski, took a populist gamer stance, saying systems that block used games "can be a bad thing."