Really nice initiative, someone needed to start to at least try to do something to reduce abuse with a different approach. How are you gonna manage the watch list? Would you be posting it regularly or something like this? I mean, as you say someone maybe do something wrong by mistake, I think that this person should be able to know that you have them in a watch list.
Keep up the good job ;)
I will be posting the watch list weekly like this. I will also be leaving post comments for anyone on the watchlist so they know about it like this.
This should give ample awareness.