I don't see how anyone could accuse you of doing anything wrong. What if you had CCTV?
I did say that it was an extreme example but it could come down to a matter of interpretation. In the publics eye there is (in my own, unsupported by evidence, opinion) a difference between CCTV footage captured by overt CCTV cameras with signs advising of CCTV in use and with hand held video footage of school boys, captured from behind the cutains.
I just think in the Ireland we live in today people can very quickly jump to the wrong conclusions when you tell them you are video taping school children.
Try reversing the situation slightly - what if the OP was male (I am assuming from the username that the OP is female) and the school kids were young girls - would you still be recommending video taping them?
Maybe I am just scaremongering and should have more faith in my fellow man - it was just my initial reaction when I saw the suggestion to video