I haven't been active there in a couple of years. The signal to noise ratio makes the website useless. Not enough quality projects and not enough projects with realistic budgets.
But the problem with fraud is beyond serious. I am very careful with who I do business with, and screen customers as much as possible, but their platform really makes it easy for fraudsters to screw you over. I got a couple of issues there over the years. They both were very small amounts, like $200 or so. In one occasion the customer just reversed the payment, stole my code and freelancer.com did absolutely nothing to stop him. In another incident, the customer did not release the payment after completion of the project and I had to settle to accept only his initial deposit as payment, which was like 20% of the agreed price.
The company is also very fee hungry. There are hidden fees everywhere for everything you do in that website. The website itself is also terrible. Customer support is the worst I've ever dealt with.
There are much better ways to find customers than these kind of websites. On the other hand, if you are looking for developers there are plenty of good ones there, just avoid all the Asian body shops and your chances of successfully finding someone are actually not that bad.