[quote=@Mr Allen J]
[@Mahz] This was an idea I just had, but what if you can add little reasons why you're banning someone from your thread that show up for them (and co-gms)? 
[/quote]
This could easily be abused. Send a PM to the person and say why they're banned. I don't believe that banning should be used for your personal blacklist, but only for important reasons (like they won't stop spamming your thread).