Lest one of them "accidentally" walk away from the cafe, they are outfitted with alarms that will go off if they're removed from the area. And this is certainly an eco-friendly solution. But is it a good idea? First, mixing expensive electronics with food and drink isn't the safest. And who knows how many people have touched the thing before you? Although, perhaps it's no different than using an iPad for a menu or a wine list.
What do you think?
Source: Flickr User henribergius