My biggest pet peeve that I see all the time at my field. Someone who thinks or pretends he knows it all and screws up someone else's plane/radio program and then walks away leaving the mess for some other big ego to come along and screw up some more. Plane crashes and no one takes the blame. Some poor guy who really can't afford the loss is now left with this mess while the egos move on to help "solve" someone elses problem.