I'm currently taking a course where I acquired the textbook as an e-book. Physical copies were available too, but I find kindle-versions far more convenient as I can read it wherever, whenever, using the kindle app on my phone.
Then naturally during lectures, I'll have my phone out (on mute of course) so that I can access the book. This is no different to any other student in the hall who have their physical copy out. In fact, I am less disturbing, because when those other students need to look something up, you'll hear pages turning, while my finger is silently scrolling my phone.
And yet, my professor doesn't seem to realize the benefits of technology and bans usage of phones. I of course do not intend to follow this policy: I've paid money for my e-book and am not going to spend more money for another physical copy just to appease this tosser.
However, my question is specifically, what should I do? Should I just keep on using my phone as usual, or should I contact some authority figure immediately? I'm not really worried about what he can do (because there's not really anything he CAN do, he can't throw me out of class or anything), but I would still like to take optimal steps.