Essentially it stipulates that they will assess the risks of back flow at my property and determine whether or not a back flow prevention device is required.  

So we are looking for the same functionality with the added ability to populate directly to everyone's calendar, send notification when new tasks are created and integrate with all devices we use...and of course give our portfolio managers ability to run reports to ensure timeliness and thoroughness.  

So anyway, unless you are smarter than me, that kind of thing can happen... that's the reason there is no perpetual motion machine and no free electrical device you can build in your garage.

All contracts, options, or other devices not based upon a substantial consideration, or that are otherwise employed to permit an unlicensed person to sell, lease, or let real estate, the beneficial title to which has not, in good faith, passed to such party for a substantial consideration, are hereby declared void and ineffective in all cases, suits, or proceedings had or taken under this chapter; however, this section shall not apply to irrevocable gifts, to unconditional contracts to purchase, or to options based upon a substantial consideration actually paid and not subject to any agreements to return or right of return reserved.

I actually did this a few years ago with water (I submetered the units and wrote into the lease that there was a flat charge per person but that I reserve the right to install submeter devices at any time and then bill tenants accordingly). 

Or send your handyman over to the house, and have them flip off the power from the main circuit breaker box, and have them put a lock on the circuit breaker so that the guest cannot turn it back onThank you very much for your answer and all the great advices on good and useful smart electronics, that is something that we definitly would like to invest soon, those things really make a diference not only making the property more attractive with those gagdets and devices but will also be very useful in these kind of situations that we always need to prevent! 

You can attach a ton of devices to it for full smart home usability.

But for the internet access to a ROKU device, you are limited to 24 devices. 

There is an answering device on the line--I check the messages once or twice a week.

Each has its own accepted return threshold and they can often be vastly dissimilar.