Contact some university activists too.
They have passionate attachment to the Little Guy.
Media students can be very creative. This is a spontaneous student project from several years ago in response to General Electric's massive ad campaign to avoid dredging the Hudson River to remove toxins disposed of there by the company. The students made a billboard-sized banner and fastened it over one of GE's own billboards as a non-destructive protest. Thanks in part to numerous student activities supporting citizen groups, GE lost its bid and was required to clean up the river.
You can't control them once they're interested, but when you explain what's needed, and what's counterproductive, they can be amazing.