R4 cartridges banned in UK
The cartridges, which are popular for storing illegal copies of Nintendo DS games, have been categorically banned in the UK following pressure from Nintendo.
It might be okay to jailbreak your iPhone or iPod touch in the US, but it's not okay to own an r$ cartridge in the UK. Develop reports on a crackdown on the popular pirating device.
Used by those seeking to illegal download Nintendo DS games, the special cartridge is able to hold dozens of games on a single cartridge.
Unfortunately, the move threatens anyone using R4 cartridges for home brew games. Although the UK government acknowledges this, the use of R4 cartridges requires bypassing Nintendo DS security protocols and so therefore is disallowed.