In writing the opinion of Integrity Staffing Solutions Inc. vs. Busk et. al, Justice Clarence Thomas clearly was not thinking about handing unions a powerful new tool for unionizing. Instead he was thinking about how it was fine for any company to restrain and employee for hours each week without any compensation. But, in his wording, he may have just struck down right-to-work laws nationwide without realizing it.
These arguments are properly presented to the employer at the bargaining table, see 29 U.S.C., 254(b)(1), not to a court in an FLSA claim.
Per this section of US Code, the issue of a workplace retaining an employee without compensation for hours each week is one which must be handled in negotiations between the employer and the employee, their agent or their collective bargaining representative. This statement, as simple as it is, has a lot of weight behind it due to the nature of the case behind it. By retaining the full text of the Fair Labor Standards Act (FLSA), combined with this decision, the entire workplace dynamic for collective bargaining just changed overnight.