"TSA really doesn't have a sense of humor"
Actually, the guy who tweeted specifically called out the TSA for being the most reasonable of the involved agencies, because they basically weren't involved. The FBI was the group that detained him.
Better coverage here: http://www.papersplease.org/wp/2015/04/20/does-an-airline-have-the-right-to-refuse-service-to-anyone/