http://splitsider.com/2014/07/the-social-media-graveyard-of-canceled-comedies/

So many dead TV shows had Twitter accounts, it’s like a social media graveyard.
Read more at http://www.hitfix.com/tv-tattle#1VgyoCDyE4OFP0WD.99

They need rebooting.

I think if a cancelled TV show ran for one, two or three seasons, its Twitter account should just be deleted. Cancelled shows that ran for four seasons or more can keep their account.