The Mexican government has been battling corruption in a big way for the last decade. The battle has not been going well. It all began in 2000, when the PRI (Institutional Revolutionary Party), which had been running the country for 70 years, and had the corruption down to a science, was voted out of power. The new government got elected in part by a popular desire to get rid of the corruption. One of the biggest problems was with the deals PRI had made with the drug smugglers, who moved cocaine (from South America) and marijuana and meth (from Mexico) north. Suddenly their illegal activities really were illegal. Rather than let the government shut down these lucrative enterprises, the drug gangs went to war with anyone who came after them, and each other. Over 30,000 people have died so far, most of the violence taking place along the U.S. border. Economies have been ruined, local police departments crippled and news media cowed into silence.
The government has sent in the armed forces to deal with the fighting. But at the same time, there is also a major effort to clean out the corruption wherever it may be found. This includes getting rid of the corrupt border control agents. Theyve already been making clean sweeps of older personnel at border crossings, replacing them with new people, but additional measures have been taken recently. Many of the new border and customs personnel are former military, who are more disciplined, trustworthy and patriotic. In addition, the government appears to be randomly shuffling personnel from post to post. This includes specialists like veterinary inspectors (U.S. livestock is an major import to Mexico), as well as the inspectors who check people (and vehicles) coming and going. Some inspectors are shifted after only about 4 months on the job, although it's more common to be transferred after about 12-15 months. No corruption charged or suspected, just keeping the border staff from getting too comfortable, and tempted. This is tough on the personnel, since it means displacing their families, and the government doesnt pay moving costs. The government is depending on the new inspectors, like the population in general, to be angry enough about the corruption to put up with all the transfers and oversight.