The airdrop itself is not a scam - it is a legitimate airdrop that the Omsie Go company will be doing at some point. The scam is the website linked above - that was created as a way to get peoples private keys from their ETH wallets to steal their coins. Although I do not think we have confirmation yet that the airdrop snapshot has already taken place or if it has not. I am unable to find good details on this anywhere.