Just because you can think of ways out of enforcement doesn’t mean all enforcement is impossible. If there’s a plumbing truck parked at the movie theater, management is going to damn well know if plumbing work is occurring. I know it makes us feel smart to think of loopholes but we don’t need airtight enforcement in order for a law to make sense. There are tons of laws on the books that aren’t actively and exhaustively enforced, and they exist to give authority to those who would take action in situations where they can.