You should expect to see a mix at large demonstrations. Some people will make their own, others will be attending with a local special interest or political gro

You should expect to see a mix at large demonstrations. Some people will make their own, others will be attending with a local special interest or political group who may be more organised and print matching signs. For a small demonstration, it may well be attended by members of the same organisation that organised the demonstration. All the matching signs prove is that only one organisation is significantly involved. If strikers on a picket line have matching signs made by their union, does that mean it’s organised by a shady institution and not a genuine effort by people. It seems strange to me to require small demonstrations to pretend to not be organised. I think better heuristics should be found.