Your Papers, Please! How would you enforce it?
They have targeted a tire store in Salem, NH in particular and yes they want to force the company to check papers (i.e., driver's licenses).
Years ago I remember a story about MA state cruisers parking in NH Mall parking lots and writing down MA license plates with the intent to follow up to make sure they filed MA sales tax paperwork. The MA state police were supposedly "escorted" out of the state by the NH state police. I don't know if it's a true story or an urban legend.