Thank you! However, as I understand, an user may have already answered or asked a question without receiving any points. The problem that I have actually is that I was careless in the past and my qa site was populated by about 50k bots. I want to remove them. However, there is no easy solution but it seems that the solution that is the closest to the one that I am looking for is (1) to remove all the users that have not confirmed email; (2) to remove other users that come for a list suspect domain sites that do not have generated questions, comments and answers in the site; (3) to test the reminder ones using botscout for instance. It is worth mentioning that the anti-bots systems are great to avoid bots, such as the one that you have created (thank you), since the 10% that it is not able to detect we can remove manually. However, in my case, 10% of 50k is still are very large number and I am looking for a mix of solutions and strategies.