A bit of fact checking, please. You quote event organizers on the crowd size, and print the "2 million" figure from a participant, but nowhere is there any common sense reality checking. The crowd here this weekend barely stretched across Third Street, which divides the Capitol grounds from the National Mall, which translates into somewhere between 50,000 and 75,000 depending upon how closely packed people are.
Look at pictures from Inauguration Day last January, when crowd estimates were in the 1.5 million range. The crowd that day stretched from the Capitol steps beyond the Washington Monument -- more than a mile and a half. The crowd on Inauguration Day literally closed the government center of the city. The past weekend's event put no more strain on the city than an NFL game, and it might actually have fit in FedEx Field, home of the Redskins.
None of that is a comment on the content or purpose of the event, but rather a simple plea to get the basic facts straight.
No official department in DC does crowd estimates, because they are always controversial, but simply looking at photographs of the event and comparing them to past events for which academic crowd measurements have been done can give you a reasonably accurate estimate. All it takes is about 10-20 extra minutes of research on the part of your reporters.