Anytime I go into my telegram account, I see countless number of airdrop with countless offers but the challenge is trying to know which of this airdrop that is genuine.
If users can't sell their tokens or if this isn't listed on coinmarketcap then is better to stay away from that airdrop because those are coins without value. Maybe in the future, those coins get a value, but that's a bet, maybe the coin never gets listed.
Or take a quick look at their website, you will already get impression if the project is fake or not. Because if they do have generic content, high likely that they are just fake. But if they have solid foundation and all the documentation is there, probably they are running a legit project but you need to study more on this project.
It's no longer effective in my point of view, scammers are already doing the copycat of true project. They can imitate easily how real developers build their websites.
Most of the time, hunters are all relied with luck following or participating with any projects who offered this bounties.
Keep yourself well aware and stop providing important information such as KYC and if there's any fees most probably it will turned to scammed out.