it shouldn't ever be necessary to submit KYC for airdrops or bounty stakes because the amounts are way too low qualify for reporting under money transmission laws.
some ICOs do it because they are misinformed about the law. some do it because they think it will make them appear legit. some do it because they want a way to avoid paying some of their bounty hunters after the fact. some do it because they are going to sell your documents on the darknet.
none of these reasons are legit. don't do KYC for airdrops or bounties!
I believe a few countries have restricted the circulation of cryptocurrencies in their country. I mostly see, USA and China.
As per SEC regulations this ICOs are requested to prove that their investors or contributors are not from countries where digital currency is illegal.
It is quite a gamble. And most times, the risk is not worth it.