I found a link to the traffic cams around DC.....should give a good idea of what the "people traffic" looks like in the area surrounding where this "Peace Rally" is taking place
http://www.trafficland.com/findacam/trafficvideo.php?uid=0&map=142
Looks to me like they are all pretty much gathered in the one place we are seeing on CSPAN much different that the ANSWER guy suggested ('member he said there were people lined up and down Pennsylvania Avenue?---doesn't look like it)
So my husband says that when they say that "hundreds of thousands of people showed up" they probably mean "a hundred or thousand people" showed up.
Looks to me to only be 500-600 people.