When we have done KYC on any platform, it is likely that they can trade our data, even on trusted platforms because hackers can penetrate the security and steal the users data on that platform.
-snip-
Yes, I have received several emails and sms some time ago, I previous joined BCNEX campaign and I did KYC there to get payment, so I immediately remembered that sms and email I received came from the data they had sold
Are you sure you have only done KYC in that bounty?
BCNEX is one of the bounties whose project namely exchange, becomes a scam.