Tony Mendez, Letterman's long time cue card guy, has been fired for assaulting a writer for the show:
http://nypost.com/2014/10/19/late-show-cue-card-man-fired-after-argument-assault-on-writer/
http://nypost.com/2014/10/19/late-show-cue-card-man-fired-after-argument-assault-on-writer/