This is normal for almost all (all?) large corps; they don't have to tell you why the account was terminated/blocked so it could be anything; something you said

This is normal for almost all (all?) large corps; they don't have to tell you why the account was terminated/blocked so it could be anything; something you said online (about them / founders etc), something you paid they don't agree with, just ROI vs TCO for your spending habits etc etc. They don't have to tell you and 'suspicious activities' is an easy one: adsense/adwords uses it as well. They use 'if we would tell you what it is exactly and how we measure it, it will allow evil actors to use that against us'.