I can bet however that we had have many alts in the past in some of the most well paid Campaigns on our Forum.
Let me fix that for you. 
I don't know if your remember (or if it was before your time here), but few years ago there was a case of 3 accounts (controlled by the same person) being in the best campaign on the forum (CM) for years and no one would probably notice if one of the members didn't make connection via addresses. So, if it was possible to inflitritate that campaign and stay unnoticed for years, I am sure that the same thing has been happening in others as well.