“The Guild of Firefighters had been outlawed by the Patrician the previous year after many complaints. The point was that, if you bought a contract from the Guild, your house would be protected against fire.

Unfortunately, the general Ankh-Morpork ethos quickly came to the fore and fire fighters would tend to go to prospective clients’ houses in groups, making loud comments like ‘Very inflammable looking place, this’ and ‘Probably go up like a firework with just one carelessly-dropped match, know what I mean?’”

-- Terry Pratchett: Guards! Guards!