Here's an interesting topic to get debate going - what if Nintendo lifted a ROM of Super Mario Bros. from the internet and then repurposed it for the Wii Virtual Console a decade ago? It would certainly put Nintendo's policies against emulators in the spotlight.
That's the claim made in a Eurogamer video, below, which picks up on an anecdote from a GDC talk last year. The key evidence is an 'iNES' file header, found when viewing the source files for the Super Mario Bros. Wii VC download on a hacked system. This data reference is from an early set of emulated files shared online, and the evidence is rather compelling; the story is told below, including Nintendo's response and denial. [Update: some terminology in this paragraph corrected on 20th January, with thanks to Ryan Holtz]
There's no suggestion that this is a widespread 'issue', though anyone with a modded Wii may now be rushing to check. There's Nintendo's denial to acknowledge, of course - the theory that this may have slipped through via a contractor's work also seems feasible, if indeed the evidence is 100% correct.
In any case, the ongoing debate over the Virtual Console and Nintendo's approach to protecting its IPs will continue; this tale dating back to the Wii certainly adds a little extra flavour.