Size does matter!

[Jordan Hayes]

San Francisco -- A survey using sophisticated aerial photography of
Sunday's anti-war march and rally in San Francisco has produced results
that indicate a far smaller crowd than the 200,000 protesters estimated
by police and event organizers.

<http://sfgate.com/cgi-bin/article.cgi?file=/c/a/2003/02/21/MN240732.DTL
>

Interesting tidbit: the cops overestimated.