To go along with what a lot of people are saying here, as long as you're not giving them any information other than the delivery address, there's no way you can get scammed. Even if the airdrop ends up being worthless, who cares. It doesn't mean you were scammed, it just means you wasted some time on a useless token. Take as many airdrops as you can get, there's no harm in participating as long as you keep your information private.