And also, to Anton1912 & to all :
There is also a video on YouTube that describes cases of fraud, for example of a "client" that "realy like your gig", who agrees with you on a very large sum of several thousand, and after you have done the work, he informs you of something like a redemption fee, or a registration fee of, say, a few hundred, that you have to pay in order to redeem the amount the full...
and all kinds of others scams. ther are Also videos, maybe most of them old, that explain how to avoid and detect frauds like that before, as a seller on Fiverr.
So basically it seams to me that :
Fiverr both saves us the headache of being able to identify this ones, and also protects us.