Many rental properties have cameras in public and common areas. Public meaning anything outside and common meaning garages, laundry facility, gyms, clubhouses etc. Even pools.

Why would you need to contact a lawyer? Is it because this client wants to be able to remotely view the property vs viewing it locally?

Obviously this landlord has to have his own power and internet. There isnt any other way to control whether its on/working or not. Landlord cant force people to power/connect his devices.