In book 10 of Pliny's letters, that is the volume that charts the correspondence between him (as a special imperial delegate in Bithynia) and the emperor Trajan, there is a rather intriguing exchange.
In letter 33 Pliny informs the emperor of a serious fire that broke out in Nicomedia that detroyed many houses plus two public buildings, the Elder Citizens Club and the Temple of Isis. He suggests that he might form a company of firement, numbering about 150 or so also noting that any privileges granted would be monitored and not abused.
Trajan's reply is very suspicious, saying that although is it a reasonable idea it is groups or societies like those that have been responsible for political unrest within the province. "If people assemble for a common purpose, whatever name we give them and for whatever reason, they soon turn into a political club. It is a better policy then to provide the equipment necessary for dealing with fires, and to instruct property owners to make use of it, calling on the help of the crowds which collect if they find it necessary."