Their response pretty much covers anything and everything you could possibly do to get banned. They didn't say in the reacticvation email what it was specifically. It doesn't say you were banned for using a broadcaster. I'm not sure why people are jumping to that conclusion.

It could have been anything at all. The first response says you were selling kinah (not saying you did at all) and has nothing to do with multiboxing. They don't mention multiboxing at all. Gold selling, third party programs (like glider is what I bet they are referring to) and other activity is what they say.

Hopefully it was just a lame error on their part.