In response to the points you have highlighted in your message:
Yes I can see what is happening on the network, any good network manager needs to be aware of the things happening on his network.
I am not spying on you, I am checking that the network does not get abused. A number of the students take the mickey, therefore you make well only use the internet for anything other than school work during your free periods, however, other students don't, and I'm not prepared to make one rule for you, and one for the others, especially as you threaten to "crash the system".
Earlier in the year, I was going to give 6th formers more freedom, however, a number of 6th formers went too far, and I put you all back on the same policy as the rest of the school, so, a number of people ruined it for the rest of you. I would point out, that if students behave as children, I will treat them as a children.
We're you to send this message to the network manager of the company that you worked for, you could reasonably expect to be called to see your manager, and if not sacked, have a written warning.
This is not an invasion of you privacy, in order to use these public computers, you do so under a set of rules, which you agreed to in Y7, and some of which are displayed on posters around the school.
Whilst you claim that you believe "that the world wide web belongs to everybody and no one person can own it or control it.", this is a somewhat immature attitude. The www is still policed, even if you are unaware of it. Everything that is done on the internet is logged somewhere, that is how the police track and catch such people as paedophiles who use the internet.
Website such as MySpace & Bebo are blocked because social network site are actively targeted by such people, and they are experts at deceiving young impressionable children. Therefore, the school has taken the decision to prevent the school computers being used to access sites such as these. I didn't make the decision, I just enforce it.
Finally, I have never played D&D, although I am disappointed to find out that it isn't real.