I sometimes have this problem as well. Last year, they tried to ban cards, but it didnt stick well, basically because the principal knew me and my friend, so he allowed us to have them. Well, one day just like 3 weeks ago, it was a 1/2 day at school, and I was in Spanish. The teacher didnt have anything for us to do and sat at her desk while everyone had cell phones and iPods out. So I decided to pass some time by practicing sleights (nothing noisy or disturbing), keeping to my own business. But as soon as she saw me with them, she took them, even though it isnt a rule, and it made me mad because of the phones and ipods. She even knew I did magic, but I reckon she dislikes me. I still havent gotten them back. Whew, one day, she had the nerve to ask me ifshe could see something.. Such hypocrites aggravate me. Well anyways, back to you. I would like to hear the reasons, but just find a loophole. Like mentioned earlier, look into coin magic, cause they cant take your money.
technically hey arnt allowed to even take your cards away