DD (7, y3) is bright but can be a very difficult child at times. However, her school are really not helping matters - I think they have lost all sense of proportion with disciplining her. 
Last week DD bought a Practical Joke book from the school book fair. The following day she smuggled the rude-noise-making putty
into school (against my express instruction) and played a prank on one of the break supervisors (who happens to be her close friend's mum): "Oooh, is that you farting, Mrs X?"
DD was promptly hauled into the head master's office for a chat about 'inappropriate' behaviour
It was described as a 'serious event' to us parents. We obviously backed to school up 100% to DD's face, but privately I'm wondering if that wasn't a SLIGHT overreaction from school. She's 7 and bought the offending item at school FFS!