Critics of big businesses have found a new line of attack against huge companies like McDonald’s and Walmart: calling them “welfare queens” for paying such low wages that their workers rely on government safety-net programs to scratch out a living.

The “welfare queen” line of criticism has taken off partly because of studies like a recent one from researchers at the University of Illinois and University of California Berkeley’s Labor Center that found that federal spending on public assistance for fast food workers totals almost $7 billion a year, including Medicaid, food stamps and Earned Income Tax Credit refunds.