i do hate when people assert that things are 100% safe, playing any pirated stuff is never going to be 100% safe, im sure it would be trivial for nintendo to verify NNID's to purchases, its just that so far they havent appeared to be ban hammer trigger happy, these things could obviously change.....especially around the time of breakthroughs that might cause a huge influx of pirates such as downgrades becoming available to the masses

.....basically if you don't want to be banned don't pirate or cheat at all, if you decide pirating or cheating is more important dont kid yourself that your 100% safe