1. Cloud mining scam where they make users to invest in their cloud mining and give them a very small % of their amount daily and also encourage them to bring more members so they can get extra rewarded after a time when deposit amount starts to slow down and withdrawal amount starts to increase then their threshold they simply vanished.
2. Multi level marketing scam this work as from oldest days just invest an amount bring two more make your own tree and earn rewards starting ones in this scams who are able to get many other people always get profited and 99% of members who are in down ranks get scammed they do the same when incoming amounts slow down and outgoing amount reach a certain threshold they simply vanish.
3. The seed hack scammers are approaching people saying we will teach you how to make 100$ in one hour and you need to give it to us most common people don't know about seed and put their btc in online wallet such as coinbase or blockchain so scammer get their screen shared and make them transfer their btc in a wallet such as electrum and got their seeds screenshots open their wallet in their own computer and transfer the amount people had no idea what struck them .
4. Investment scams deposit x amount and get x amount this is the most common type of scams getting all over the internet it is a small amount scam usually people don't mind to fell in it by giving 5-50$ of amount to these scammers .