This guy was sitting on the train with his guitar in the aisle. Not just blocking the aisle, but out of the case, on an instrument stand, ready to play.
Admittedly, the train I take is rarely SRO in the morning because it is so flippin early, but still. Apparently he does not value his property at all, because it only would have taken one hard bump with a bag or someone tripping over their feet on a hard stop to break this thing open. Not to mention he was taking up space in the handicapped area.
Photo on the BART RAGE Flickr site: