We always review offensive posts together so we can determine if the posting member requires warnings or removal. We like to be democratic about the process and prefer one person doesn't pull the trigger (even myself).
The locking preserves them until I check in and get everyone's input on open mod issues. Preserving the thread is also helpful so I can determine the origin of the poster. Once communication/action has been taken, then I'll delete the thread (well... usually).
Call it from Heaven Chick.