I get the same attitude from
IT and administration, and I am a teacher in the school system. If the schools switched to Apple, the IT dept would be redundant, or much smaller at least. Rather than use the POS Lenovo thinkpad they provide, I just use my MacBook, tether it to my iPhone for Internet access ( up to 6 GB a month) and then I don't worry about limitations. Our school has a no-cellphone policy, but oh well. It's not a phone; it's a breakthrough internet device.
Speaking as a member of the IT dept, no.
Eggman has it right, it's THEIR network. They have policies in place for a reason. Our particular policy involves NO personal machines on the network. Be it a windows, mac, or handheld device, if it isn't provided by us, it isn't networked.
If you're bringing in a personal machine, especially as a teacher, you're opening yourself up to a whole mess of worms. Virii are the least of your(or the IT dept) worries.
I doubt iBoss has anything to do with any blocking going on, as it's easy to find out what kind of computer is on your network by checking the DHCP server to get the MAC address, googling the MAC and finding out manufacture info. Or, they could have just seen the unauthorized computer on your desk while doing something else and decided to be non confrontational about it.
This attitude of the OP and the others supporting him are the reasons the kiddies think that (insert crazy website here) is so totally ok for school, and the schools are so (expletive) (derogatory term) for thinking we should be on it. This is like saying that it's OK to take money from a cash register because it's open, or because you know how to get it open. It's against the law, and at work/school, the policy is the law. (Just like Judge Dread.)
Despite what people here think, logic and reasoning are what make the best IT folk around. In this case, they have logically concluded that as they don't have admin rights to your machine to make sure all security patches are up to date and because they maybe don't have a OS X version of their chosen AV solution, that it is safer for all to no longer allow access.
fjn, I appreciate your resourcefulness as a fellow tech enthusiast, however I hope no one in your school/district's IT dept is on this site. Knowingly violating policy, publicly bragging about it, circumventing internet access policy... well it could be an outcome very unfortunate for your career.