By Jim Reed
Newsbeat Technology reporter
Thousands of illegal hacked titles are available to download for free on file sharing websites
Getting your hands on free handheld console games from the internet, could become a thing of the past if Nintendo has anything to do with it.
The company is taking legal action in Japan to stop the sale of a device which lets users do just that.
The row's all about five companies importing the Chinese-made R4 Revolution which works with Nintendo's portable DS machine.
So Nintendo has filed a lawsuit in Tokyo District Court to try to stop them doing that.
"The device is causing immense harm to both us and our software makers. This is something we cannot possibly overlook," the Japanese gaming company said in a statement.
The R4 Revolution is the latest plug in device that lets you get hold of use copied material on Nintendo's handheld machine.
It's about the size of a DS cartridge with a small slot for a standard 1 or 2GB MicroSD memory card.
The device is sold as a way to play homemade games designed by bedroom coders but can also be used to run pirated titles.
It bypasses the "firmware" code built into the DS and replaces it with a custom version that lets users play games off the re-writable memory card.
Thousands of illegal hacked titles are available to download for free on file sharing websites.
Nintendo is bringing the lawsuit, along with 54 other game makers, including Capcom, Sega and Square Enix using Japan's Unfair Competition Prevention law.
Whatever the outcome of the case, it will have no legal standing in the UK, where the R4 Revolution is widely available from mainstream online retailers for around £10.