I have seen evidence of some scams being run under the guise of KYC in order to gain your passport and government issued id's. Be careful out there and remember that a lot of these coins end up being scams. Do you really want them having your passport/photo identification? This is how people fall victim of identity fraud so please think before sending your information in.
If you are an investor there is no way to buy some coins during ICO without KYC (at least I haven't heard of such projects).
Another issue is when KYC is required for an airdrop or a bounty - and in this way I would rather avoid giving my personal details to get those free tokens worth almost nothing.