As Dis-Member brought out, it is entirely possible to monitor network usage. Right now for free, no additional software installed, I can view the logs on my router showing who has been connecting to it and what they have been connecting to. I do this occasionally because I don't have MAC Address filtering on and want to be somewhat sure that someone isn't stealing my internet. But as Dismember brought out, chances are your KH doesn't have someone who knows how to acess or make sense of the data.
If you are really concerned though, keep a password on your device so that someone cannot get your MAC address if you happen to leave it unattended. Never volunteer your MAC Address. Let's expand this to never use your device on the KH's network, and place your device on airplane mode before you get to the hall so that it doesn't talk to their router. But if you do use their network, make sure that your device name could not identify you because some routers will store the device name and MAC address.
This only really pertains to what you do over the network though. It's much more difficult to determine what you are doing locally on your device without the aid of the mic guys.