[Skiptown]

While traveling by bus we went thru several checkpoints with many guys with automatic weapons in military dress and sandbagged bunkers . We went thru them once between Cancun and Valladolid, once between Valladolid and Merida, again between Merida and Campeche and the same on the way back. There seemed no ryme nor reason as to who got stopped and we were wondering what are they looking for. Is this just mostly a show of force and something to keep them occupied? If they were looking for drugs then why no drug dogs? One dog can do more than ten men. If there is really a problem then how often do you read or hear about them blasting someone away? I saw them going over a truck like ants on a candy apple.
Anyone know much about them?