Be wary  photographers, snapping your shutter could trigger a 911 call. At least the Chicago Transit is warning commuters to be on the lookout for “excessive” photography. Click here for the story. Photographers have a right to take photos in public, but if you’re excessive, look out. This is causing confusion with Chicago transit employees and transit riders, as what constitutes excessive is never explained. Even in NY, the police department had to issue a notice to their officers this past year that people are allowed to take photographs in public places and in the transit system, as long as you aren’t using a dangerous tripod (people might trip).

Check out the CTA poster with the warning.