It's always funny watching people go nuts and lash out when a major ban wave happens. It's always something or someone else's fault that they're banned.
Let me help you clear this up now: No, it's not illegal for Nintendo to cut you off from their service even though you have pre-ordered games waiting on there. You agreed to their terms of service, which specifies that Nintendo can cut you off at any time for any reason. And good luck taking that to court and trying to pull the "terms of service isn't law" card, because Nintendo could counter you over the fact that you pirated an unreleased game. Doesn't matter if you also ordered a legit copy; you downloaded someone else's ripped copy and installed it ahead of release date without Nintendo's permission. You didn't follow the rules of their service and you stole an extra copy of their game to boot. It's all on you, and it's over.
Just to clarify, I'm not flaming everyone who pirated the game. In fact, I did it too. I'm only addressing the people who are upset and trying to make it sound like it wasn't their own fault, to the point that Nintendo is acting illegally. I personally took every possible precaution against this kind of thing, since it's not even the first time that it's happened (shut wi-fi off, don't use my main system). Anyone who didn't take precautions had it coming and are in the wrong. If you accept that fact, you're fine in my book. But don't go claiming that it was something out of your control and/or that Nintendo or someone else did something wrong.
I think this should be put in the OP















