[newgeezer]

The workers arrested were members of cleaning crews which the company hired through a contractor. ... Employers are required to check forms known as I-9's, filled out by every new employee, ...

So, who is the employer in a case like this? I suspect it's the contractor, not Wally World. If it's like the contracting arrangements I know about, Wally World pays the contractor. The contractor pays the worker.

[twigs]

That's how I read it too. It would be the contractor's responsibility to keep the I-9s. However, the fact that this is a national sweep could indicate some Wal-Mart knowledge. An interesting story to follow.