Question: Are the investors vetted to ensure that they are qualified/accredited?

This answer is for general guidance only. It does not constitute advice.

Answer: All users do a self-registration. They have to confirm according to their disclaimer according to their jurisdiction whether they are qualified/accredited investors. So if they give some wrong answers it's fraud on their part and the platform will disable them, on condition that it becomes aware of it from a confidential source. The same is true for any other misbehavior. 

The platform doesn't check each registration manually, however, only on a random basis.