http://www.sfgate.com/technology/art...ok-3694293.php
This teacher was contracted to teach at both Facebook and Cisco, and was fired for asking people to not use their smart phones during the work sponsored classes. I'm a trained yoga instructor, and not only would a phone on or near a mat be a safety hazard, it would detract from the other people who are actually practicing yoga, and the person at Cisco who was taking pictures would be shut down so fast in any class I've been to, or I'd teach.