If you look in the Reputation board, you will surely find a lot of people who have been caught doing "illegal" things with their alt accounts. I often notice such behavior on the forum, especially when it comes to users from certain countries.

I tried to point out such behavior on one example that you can see here, but apart from me leaving neutral feedback, no one else felt it necessary to do anything. I believe that this only encourages others to do the same things, and it is no secret that some are ready to do anything for a few merits, and that includes talking to themselves.