KYC on exchange market I think is fine and not worried about our data, but for an IEO or ICO project needed KYC its not good ideas to give our data for them.
for IEO/ICO it's still ambiguous, make sure they have terms and agreements before we get involved in it. there is no guarantee that data will be safe in their hands, especially for projects that ultimately fail and become inactive.
kyc's benefits are actually good for consumer data accountability, this is useful for higher levels of regulation, but it's too futile for now because it's not useful globally.