they have those those devices that "jam" all those frequencies - I reallllly was going to buy one for my classroom....till I realized , it is VERY illegal in this fantastic country, and it did cost a few zeros......
http://www.cell-jammers.com/gsm-cdma-3g-jammers.html
damn i would love to see the kids faces when I flick the switch....
then again I want the little collars like they had in the old star trek from the 60's, I hit a button on my PAD and it shocks the shyte out of the smart ass kids that aint paying attention!!!!
Then his $600 falls to the floor and oooppppsss, Did I do that ?
Ya'll stop laughing now ya hear!