Part of what made piracy so rampant on this last generation of handhelds was how unbelievably easy it was to boot your own software. Anyone can look at the Nintendo DS's software library and recognize how flash carts like the R4 affected the way publishers viewed the system. It appears Nintendo learned a few lessons from their previous hardware generation and are employing new techniques to combat the rampant handheld piracy.
Extremely unofficial reports state that the 3DS can be bricked through a firmware update if illegal tampering or software has been used with the device. A Japanese video game shop which buys back hardware like the 3DS posted this letter, roughly translated by Go Nintendo:
"Dear customers who resell Nintendo 3DS "
"non purchase able 3DS system"
In case if you use equipment which is illegal or unapproved by Nintendo or if you do customization which is unapproved by Nintendo, there is a possibility that Nintendo 3DS become non bootable by system update.
– From Nintendo 3DS terms of agreement
Because of terms of agreement above, Enterking refuses to buy 3DS system with record of illegal or unapproved equipment.
"Request to format before you sell"
To protect from leaking your personal and internet connection information, We ask customer to format system. In case purchasing could not be established after you format 3DS system, Enterking is not responsible for lost datas and settings. Please understand before you format.