Policy says that electronic devices (e.g. mobiles, tablets, etc.) have to be switched off (or at least AirPlane mode) during taxi, takeoff and landing.
In-flight they can be used for e.g. SMS & Tel (AeroMobile) or WiFi (OnAir) depending on aircraft.
Cabin Crew didn't behave according to the rules. Probably just wanted to avoid a discussion. :/