The point is to identify officials who would do it ordinarily: his service can respond that no one else has mentioned that official, and encourage their users to ask a friend to testify too. More than establish a proof that could be legally binding for local institutions (a long shot) it will encourage people to consider how many friends are influenced, and would be ready to do something. Just talking about filling in a form, no matter how empty that process can be, sets them in a changing path. What the original comment was pointing out is to set up process to avoid adversaries of his service to discredit him by posting fake accusation, and ‘showing’ how wrong his service is; ‘vetting’ it indeed hard, but you don't need hard proof to fight endemic corruption.