A months-long investigation has revealed that Walmart has systematically used bribes to get what it wants in Mexico. Here's a key paragraph:
The Times’s examination reveals that Wal-Mart de Mexico was not the reluctant victim of a corrupt culture that insisted on bribes as the cost of doing business. Nor did it pay bribes merely to speed up routine approvals. Rather, Wal-Mart de Mexico was an aggressive and creative corrupter, offering large payoffs to get what the law otherwise prohibited. It used bribes to subvert democratic governance — public votes, open debates, transparent procedures. It used bribes to circumvent regulatory safeguards that protect Mexican citizens from unsafe construction. It used bribes to outflank rivals.
When the Bentonville big-wigs of the corporation back in Arkansas found out what was happening in their Mexican subsidiary, they opened an internal investigation. When the investigation revealed the truth, the Bentonville big-wigs shut down the investigation and covered it up.