Flew SWA today and as always, used my ipad up until the announcement to turn electronics off. And, as always, I turned it "off" by hitting the button on the top, which blacks out the screen, then went to close the case. A flight attendant stopped me and said I had not properly turned it off. She made me holddown the button on top until the red slider bar comes up asking if you want to power it off, and then turn it off that way. I was really surprised by this because I never do a full powerdown -- not at home, not on planes, not ever. Have others run into this requirement? Could it possibly matter?