David Emery gave me a heads up about this soviet-style poster that has supposedly been sighted on the MARC trains that go between Baltimore and Washington DC. It urges passengers to: "Report any unusual activities or packages to the nearest conductor. WATCH, RIDE, AND REPORT."
The poster seems so Big-Brother-like that a lot of people suspect it must be a hoax. David Emery comments: "the logo on the poster reads "MARC Marshals" which, as far as I can tell, don't exist. MARC trains are patrolled by MARC Police. Folks are speculating it's probably some sort of guerrilla art project."
The photo caught the attention of bloggers when it appeared on the Articulatory Loop blog. However, I think it appeared earlier on MDRails, which is a website of photos taken by Maryland train enthusiasts (although when I checked the Wayback Machine, I could see that the poster wasn't on there as of October 2004).
It actually wouldn't surprise me if the poster was real, but the only way to confirm this is if (1) other MARC riders report seeing this poster, and (2) MARC confirms that they put this poster up.