The title gets it mostly. On EE.SE we have recently given out a few suspensions and in almost every case they attempted to make a sock puppet and continue with their previous behavior.
If a flag had been raised for moderators of the existence of the account we could have been watching and prepared for the repeating behavior instead of reacting after many users were harassed again.
The basic process would be:
- User X from IP A is suspended.
- User Y from IP A is created during suspension of User X.
- Flag Moderators of the presence of User Y with relation to user X.
- Moderators monitor and have advantages if users continue unacceptable behavior/issues and use super secret moderator stuff.
A more broad tab notifying of coinciding users based on this alone might be interesting but is secondary to this.