Critical Mass is a form of social protest aiming to create more awareness and concern for cyclists in metro areas. This usually involves organizing into large groups and taking up at least one or two lanes of traffic during rush hour.
"Masa Critica" La Plata, while lacking in numbers (there were only about 50 of us), has the awareness card down with their bright yellow "Bici Sendas YA!" (Bike Paths NOW!) jerseys that attracted a lot of attention. We rode from Plaza San Martin down the most frequently used streets. I resisted the temptation to yell at every other cyclist I saw to join us like I usually do in LA's Critical Mass. All in all it was a pretty subdued ride, but I still have yet to participate in the hanky panky known as Buenos Aires Critical Mass, ya veremos!