I totally agree with Roadtrip. If you are told you may not use elctronic equipment, then YOU MAY NOT. I suspect that you realise that what you are doing is stupid, irresponsible and illegal, which is why you try to conceal it.
Disobeying a lawful command of the captain will render you liable to arrest upon landing, fine and possible imprisonment for endangering the aircraft.
If you think you know better, carry on - but don't whinge if you suffer the consequences.