Immature, emotionally little children who were never given love by their mothers, and if present, fathers crave attention and spamming these forums is one way to get it. Having gone through a period during my youth when I did some unlawful things to gain attention I can understand their motives. I feel sorry for them. Hopefully they are young adults also and will grow out of the desire to harm others as they mature.
Fortunately, now that I know how to just scroll down past the spam it is a very minor nuisance.