The IRS employs approximately 100,000 people. Apparently none of them are paid to actually look at the tax returns we're all forced to file. According to the Washington Post, over the last two years, the IRS has mistakenly paid about $30 million to people claiming a tax credit for slavery reparations. There is, of course, no such credit allowed under the tax code. The Post tries to portray the recipients of these credits as innocent dupes of scam artists and urban legends, but it's a little hard to believe that they couldn't figure out that the credit didn't exist when they looked at their tax return and couldn't find a line to put it on.
Then again, Paul Krugman is a nationally prominent economist, and he sees imaginary line items on the 1040, so maybe I shouldn't be so judgmental.