Very little danger in actuality.

And it's possible he wasn't even actually using send/receive functionality, which is permitted for devices where it can be turned off (aka "airline mode" on cell phones, PDAs, etc.)

Still, I have witnessed a growing disregard for the "all electronic devices must now be turned off" rule, seeing pax around me continue phone conversations, play video games, etc., all throughout taxi and takeoff. Not to mention the number of ringers I have heard during flight of late.

The most annoying are the self-important people on "business" calls, who when caught by the FA and told they have to turn it off, totally ignore the FA and perhaps at last remark to the person on the other end, "Look, I have to go--the stewardess is being a real nazi," etc.