Luckily for you, this feature is currently in development in StuffPlug 3:
quote:
Originally posted by StuffPlug forums - Introduction And Upcoming Features
So here goes, some of the new features you can expect in StuffPlug 3.1:
- GroupBlock
Basically GroupBlock adds back to Messenger what should've been there from the start. The ability to block or unblock entire groups, and not just individual contacts. You can see a screenshot of this feature right here
As a tester of this wonderful piece of software, I can assure you that when you'll get the FINAL, it
will work.
/ 
