Only after school were teachers laxe for obvious reasons. During lunch time we were not expected to use phones.
- 2007(7th): The mosquito ring tone was a popular notification ring tone. I recall a friend testing it with my math teacher during class. He could not hear it.
- 2010(10th): The last time I recall passing notes in class... I got caught. Apologies to my Geometry teacher. He was one of the best teachers I had.
- 2012(12th): I(late to the party) bought my first phone... The only time I recalll using my phone was when went to the bathroom and accidently dropped it in in the toilet. :'( ... 3 days in a bag of rice and it worked just fine. I'm sure I must have used it in the toilet too many times for that to have happened, but I don't recall ever using it in class, as the punishment was confiscation of the phone and it wouldn't be returned until a parent signed off in person.
Much more likely the case, the phone makes a sound, vibration or otherwise, and gives away the child's location to a would be shooter.
I remember being 'caught' with a Game Boy Advance, tried to hide it, teacher saw me, and actually told me it was fine.
This is Melbourne Australia.