Netiquette commands that the device be held in both hands with thumbs akimbo.
So sad but true. One of these days, evolution is going to wake up and take a look around, and there will be some changes! Humans will stop growing legs because we can't check the mail without some form of transportation, our elbows will no longer function because they are always bent to hold a phone to our ear, and common sense will become considered a thing of the pa... Nevermind. That last one is already a reality.