Whilst at a traffic light....

So on my way to work this morning I was stopped at a red light when I looked in my rearview mirror and saw a fire truck stopped behind me and the thought crossed my mind... do emergency vehicles get in trouble? Let me explain.... if I were to go through a yellow light and a policeman saw me, I would get a ticket and points on my license (unless you get a really nice guy who just gives you a reduced ticket, I put that down in part to our bumper sticker, 'I love HR', real ice breaker!). However, if that fire truck who was stopped behind me was to do the same thing when their lights were not on, would they get pulled over and ticketed? My natural impulse is to say no, I feel like there's probably some unwritten code where they all watch each other's backs and let driving infractures slide.