While it's good that people turned out for this event, it's physically impossible to fit 300,000 people into 10 city blocks.
For size comparisons: football stadiums often seat 50-70,000 people. The Superdome seats around 72,000 and Michigan Stadium in Ann Arbor seats around 110,000 people (http://en.wikipedia.org/wiki/Michigan_Stadium).
It's really dishonest for protest organizers to publicly announce wild attendance figures for their events. It is extremely hard to count people in huge crowds, but leftist organizations consciously lie on a consistent basis about protest estimates. Let's aim for honesty, accuracy and a bit of humility.
Chuck -------------------------- Bread and Roses Web Design serving small businesses, non-profits, artists and activists http://www.breadandrosesweb.com/