Freezing of accounts does not only follow violations of the exchange's TOS or fraudulent activities. Sometimes it is done out of mere suspicion or probably out of nothing at all that it makes the user wonder how in the world his/her usual activities became suddenly suspicious that they warrant such drastic measure.
   

Again, not a guarantee.


Let OP be informed that while Binance has relatively lesser complaints than the likes of YoBit or HitBTC, they also suddenly require KYC from certain users who are making transactions well within their non-verified limits.