Most of those arrested weren’t Wal-Mart employees. Instead, the alleged illegal aliens worked for outside firms hired by local Wal-Mart managers to clean the aisles while shoppers sleep. While a typical Wal-Mart employee earns $7 to $9 an hour, a subcontracted janitor might earn about $6, and that math is one reason why roughly 700 of Wal-Mart’s 3,000-plus U.S. stores outsource their cleaning. A Wal-Mart spokesperson says the company “entrusts” its contractors to hire only documented workers, denies its executives were involved “in any scheme involving illegal workers” and promises to cooperate with authorities. The government hasn’t arrested or indicted any Wal-Mart execs yet, but one law-enforcement official tells NEWSWEEK that Wal-Mart itself–not any contractor or outsider–is the “focus” of the investigation the Feds are calling Operation Rollback, in a snarky reference to Wal-Mart’s low prices.

Whether or not the Feds can prove corporate complicity, the investigation has provided new fodder for debates over U.S. immigration policy. Because America relies on immigrants for much of its nannying, fruit picking and office cleaning, advocates say they should have easier access to citizenship instead of being dragged in handcuffs from jobs the rest of us are thankful we’re not doing. Others criticized consumers for being clueless about how substandard labor costs drive Wal-Mart’s “Everyday Low Prices.”

What’s abundantly clear is that Wal-Mart didn’t need this black eye as it works to clean up its public image. Last year it hired a “reputation management” consultant to research Americans’ opinions of the retail giant. The company says most of the results were positive, but they did show that many people believe Wal-Mart employs mostly part-time, no-benefits workers. That’s not true, so Wal-Mart is airing TV ads in which employees explain how great their jobs are. The company says it plans to promote thousands of hourly workers into management jobs over the next few years. In the wake of this scandal, it’s a safe bet it’ll soon be hiring more janitors, too.