Originally posted by khuon
I have not participated in any Critical Mass events but I have participated in Critical Mass-like events. These were rides that were organised either in conjunction or with permission and support of the municipality. All cyclists were required to follow the laws of the road pertaining to bicycles or were only allowed to deviate with expressed consent of the traffic officers (ie. riding in groups of more than two abreast on closed off streets).
The type of events you describe differ from critical mass in one very important aspect. These events are about fun, they are about getting people out to ride and enjoy the experience. This is totally different from the confrontational mentality that is critical mass. In short, these events will encourage people to ride more, critical mass won't do this.