David Letterman didn't hold back in calling out Paramount for acting out of "cowardice" in canceling his former CBS program, "The Late Show."

The cost of producing late night programs has risen as the media industry has been upended by streaming and shifting consumer habits.

David Letterman delivered a fiery rant against CBS and parent company Paramount for cancelling Stephen Colbert’s “Late Show,” calling the decision “gutless” and “pure cowardice” as he labeled his successor a martyr of the network.