Obviously, the threat of banning on /b/ doesn't work. People still post CP and other people's personal info (see V-chan). So instead of banning, is there any way to kind of tag these people to identify them when they post?
If you had a proper way of identifying and tracking these people through proxies, then you wouldn't have a problem (re)banning them in the first place.
"Tagging" people is a worthless idea. (What exactly would you want to tag anyway?) Keep banning them and deleting the illegal content.
What proxies? /b/tards have gotten most of them banned by now. The ones that are evading it just don't have a static IP. And are you going to ban each one until they run out?