If there is a regulation that says you can't do something, it's not there to make sure it doesn't happen, it's there so when when it does happen you have legal

If there is a regulation that says you can't do something, it's not there to make sure it doesn't happen, it's there so when when it does happen you have legal recourse to sue the fuck out of them. If a hotel is required to maintain a standard of privacy, then you better believe the brand tries to maintain some compliance to that standard. If Marriott found out that one of it's hotels was putting recording devices in their rooms, you better believe the corporate office would come down on that hotel. If not for legal reasons, public image and brand reputation.