A thousand people is much smaller than that. I've been in marches of five thousand or so and they're not really that impressive. Latest counts for this march are 400,000 and it's certainly not all in the frame.
Here's a video of a march in Montreal from 2012 that was claimed to be around 200,000 by organizers and "tens of thousands" by media.
Keep in mind they were resisting against a local government with far less economic interest in the point of conflict, and they didn't get a damn thing until they started pulling shit like this for months on end: