I'm with El Commandante on this one, but I'd add one more thing:
Everyone should remember that a protest march is an exhibition. They are good to have and draw attention to a subject, but they, by themselves, will not change anything.
People don't see a protest on TV one day and decide to go to one the next day.
These things take time and work. They require convincing people of the rightness of your cause. They require constant and unrelenting focus by people who are committed. They require staying on message and not being distracted by detractors.
Fifty thousand people just don't show up someplace and start protesting. These are people that have become committed to a cause. Maybe it's something that they read somewhere. Maybe it's something that happened to them. Or maybe, just maybe, it's something that you said four months before the protest that's been rattling around in their brains ever since.
Protests are great. Go to them. Have fun. Network. But always remember that the hardest work is the rest of the time.
vox
Economists have provided capitalists with a comforting concept called the "free market." It does not describe any part of reality, at any place or time. It's a mantra conveniently invoked when it is proposed that government do something the faithful don't like, and just as conveniently ignored whenever they want government to do something for them.