One issue we've run into when moderating is problem users who leave on their own. It's great when they do, but there have been occasions where we want to keep an eye out if they come back.

It would be great to have a command like !watch that would notify us if somebody resurfaces. e.g. !watch @user#1234 they were being super shady and might be scamming. The next message @user#1234 sent would notify mods, then stop watching them.

I'm not sure how we'd persist this across bot reloads. Often we have people show back up after weeks/months away, so it's important it's persistent.