While working as governor of Bythnia-Pontus, Pliny (the younger) travelled around to various cities, making sure finances and such were in order. Nicomedia was the capital of Bythnia at the time. Pliny travelled to a neighboring city, Claudiopolis, which had just been destroyed by fire. Pliny concluded that had the city had a fire brigade, the damage would have been less extensive.
Fire brigades (or collegium fabrorum) were common in the Western part of the empire. Pliny wrote to Trajan, requesting that a fire brigade of only 150 men be assembled in Nicomedia in case of future happenings. He writes in the last part of his request, "...it will not be difficult to keep such small numbers under observation."
It was precisely groups such as these, those assembled for non-political purposes, that ended up causing so many problems in the province.
Trajan gives an odd (or expected, depending upon your view) response:
"...but we must remember that it is societies like these which have been responsible for political disturbances in your province, particularly in its cities. 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 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."
The word used here for "political club" is hetaeria, the same word that Pliny will use when writing to Trajan about the Christians. Trajan was so worried about groups forming against him that he denied the capital city of Bythnia a Fire department!
*Attached is a picture of yours truly in his turnout gear while at a training burn for the Fire department. That's right, ladies, I read Koine Greek and put out fires...the best of both worlds.
**I didn't even think of what's going on in Southern California when I wrote this. Hopefully this isn't taken as being untimely or insensitive.