It's true to read rules of events like free spins before joining it. If you see rules are not attractively good enough or contains some requirements you don't like because you see it violates your privacy, simply ignore those events.
Right if you are not comfortable with the rules then don't participate at all in them because after that you won't have any excuses and we are not forced to do anything.Like for KYC if we are comfortable with it we can proceed further and if not then we have choices also so choose accordingly.
people always complain about KYC even though if they want they can just choose another casino that maintains their privacy, after all there is no compulsion to play at a casino that asks for KYC, everyone has a choice so before playing don't continue if you really don't like the existing rules including KYC .