Recently a incident happened where Citibank seized account giving reason for crytpocurrency transaction. Since now we are dealing with p2p then how can bank get to know that this txn is for crypto purchase. After investigation reason came out that user put in the remark as "bitcoin" while doing NEFT/IMPS transfer. Practically bank can not trace the purpose of transaction in p2p model as we are sending money to people like us and not to any exchange. But be careful and don't put any remarks related to crypto while doing transfer. May be the case, in this tweet user might have put in something like this in remark.