Bad news for Walmart. A federal raid of 61 of its stores resulted in the arrest of 250 undocumented workers who worked at the stores--mostly on cleaning crews.

The arrested workers were employed by contractors (or subcontractors, the article seems to use the terms interchangeably) who supplied cleaning crews to Walmart. They were not direct employees of Walmart.

Authorities said Wal-Mart and its executives, and not the cleaning subcontractors, are the focus of the latest probe. "They are looking to see if Wal-Mart was involved -- did they have knowledge of the contractors' practices and turn a blind eye to it?" said a law enforcement official who asked not to be identified. "How far up does it go?"

If they are not going after the subcontractors, does that mean the feds gave them immunity in exchange for incriminating testimony and evidence against WalMart? Is this just another case of purchased testimony? If so, we say take it with a grain of salt.

Meanwhile, the undocumented workers, who occupy the lowest rung on this totem pole, are facing deportation proceedings.