this is also a good business to make the profit and giving the loans like with cryptocurrencies is also been profitable for because in future cryptocurrency is mostly the popular payment method and if you got lots of cryptocurrency and then it will be more valuable.
Not really good if the business owner doesn't know how to operate his business. There are certain rules for the owner after allowing someone to borrow your own money/cryptocurrency to make sure they can pay you because once they are gone you can't get back the money to lend to them. And it is not that easy to trust someone behind the internet to be honest.
Exactly, if you don't know how to run this business then you will only be an easy target for fraudsters, I have tried this business several times, it's quite profitable, but some users do use this method to cheat, they occasionally use their accounts for collateral, and I suggest for you to never accept account bitcointalk for guarantee, search another valuable collateral, you don't know how bad the account is, so don't ever receive a risky collateral.
once again if you don't know how it works then this business will be very risky to you