And should private sector employers fire their employees for using their computers to do the same? Obviously I don't want to see teachers goofing off on social media instead of teaching kids, but if they aren't actively teaching, why not? The idea that every second of your time on the job needs to be spent furiously working is an attitude from the industrial revolution - I would have thought these days we were more interested in results.
in the school where I most recently taught, there was an explicit expectation that teachers could use district computers for personal business when on break. Being on facebook when they had kids in the room would be an entirely different matter.
The internet was also heavily monitored, with a proxy server that required a login to get to forbidden sites. Our IT guy had a pretty good idea of when teachers were getting on facebook etc.
I wish we could fire teachers for using their computers for Facebook and Amazon shopping during the day.