I have been dealing on the internet more or less fulltime since 2004 and it has always been full of scammers... The best strategy to avoid being scammed, is to always keep your crypto in a wallet you trust on a device your trust (I say this and right now I have EOS on Binance, which is only until I find a good wallet) and if you want to trade with other people, only trade with people that have a public reputation, like being on Steemit with their full identity, then if they scam you, then you can make it public and punish them this way.

Other then that, avoid all kinds of shady deals.