Wal-Mart has settled Department of Labor claims that many workers were mis-classified as exempt.  Exempt workers are not paid overtime.  4500 workers were part of the suit.  The settlement includes $4.8 million in unpaid overtime wages.  See Workplace Prof Blog.  As Workplace Prof mentions, Wal-Mart seems to always be in violation of one workplace law or another.  Civil penalties of over $463,000 were also assessed due to the repeated nature of these violations.  See DOL news release

The DOL investigation was regarding vision center managers and asset protection coordinators for Wal-Mart.