Bad news for those that plan on using a flash card with their 3DS -- if Nintendo detects that you've been dabbing with one, the company might send a firmware update that could possibly brick your system. According to GoNintendo, Japanese retailer Enterking posted a warning message on their site, suggesting that your system might be unbootable after a software update if Nintendo detects you've been using an R4. Enterking is not buying used 3DSs that have a history of using an illegal cartridge -- a transparent indication that it's not taking any chances here. We can't know for sure if Nintendo will dish out said update or how Enterking might tell -- however, Nintendo did issue this statement to Eurogamer in response to their story on the topic:

"We do not discuss product security details (for obvious reasons), nor can we discuss the details of countermeasures available in the Nintendo 3DS system. Nintendo 3DS has the most up-to-date technology. The security has been designed to protect both the creative works in the software and to protect the Nintendo 3DS hardware system itself.

Nintendo, like most companies, takes a palpable stance against piracy. We recommend that those fortunate enough to own a 3DS stay away from the flash cards altogether, just in case.

Update: Flash cards aren't illegal to use per se -- homebrew, anyone? -- although certain countries have banned them from import and sale, and their widespread use for illegal activity makes them a dubious proposition quite often.