Typically, someone who is answered by Joe Mama will go around spreading news. After they spread the news they lay in bed wondering what went wrong in their life.
The words Joe Mama being answered to the simple question of who Joe is has made millions of Americans commit suicide.
Originally just a simple joke. If someone asks this you respond with "Joe mama" but nowadays it's more of a creepypasta. If you ask "Who's Joe" then joe will come kill you sort of thing.