Shitter is a social media outlet featured in the Season Seventeen episode, "Let Go, Let Gov". The app is a reference to Alec Baldwin's Twitter account and the controversial and insensitive things he shared.
In "Let Go, Let Gov", Eric Cartman believes his Twitter account has been compromised by the United States Government. His friend, Lawrence, tells him about Shitter, an app that broadcasts the user's thoughts directly to other Shitter followers heads, as well as to those around the user that do not use Shitter. Cartman then uses Shitter to broadcast his updates on his breaking into NSA. Shitter's only users were Alec Baldwin and Cartman.