[MiddleEndian]

>Surely these were never enforceable, but I guess people don't know better.

Even if the worker knows it's unenforceable, it's still a threat and the worker would have to fight it in court if challenged.

If I walk up to someone half my size in the middle of the day and threaten to beat them up if they don't give me their lunch money, it's still a threat even if that person knows it's illegal and suspects I'm unlikely to actually beat someone up in public.