This practice by ICO teams has been going on for a while now and this is also one reason why I stopped doing bounties.

Bounties like terragreen are hiding behind their "the has the right to change the rule as they see fit" policy. They don't disclose the KYC requirement at the beginning because many are not willing to disclose their personal info just to receive bounty rewards worth a few dollars.

I like the term KYC-scams btw.


EDIT:
It appears hunters have the option to sell their bounty stakes for ETH on an exchange. Those who bought those stakes will have to undergo KYC also before they can convert the stakes into tokens.