The title should summarise this fairly well. Basically, this refers to several of our Maths rooms, including my own. As if the small windows, that are placed to high too comfortably see out of without being stood, didn't create enough of a prison-like atmosphere, the windows in the doors of Maths rooms are now being covered over with card or paper - completely cutting us off from the outside world. Every lesson in that room feels like I'm in a jail cell - and with a plateful of Algebra, fractions, and theorems sat before you, it doesn't get much more hellish.
But not only does it make you feel cut off, it also has very impractical implications. Our Mathematics teacher has claimed in the past not to just walk in without being asked, and has yelled at us many a time for it. But on many other occasions, he has asked us why we were waiting outside, and yelled at us for this too. So which does he want? I don't think even the Führer-esque teacher knows.
With the window now covered off, we cannot see if he or anyone else is in the room, and therefore are never sure which action to take. When we questionned why there was paper over the window - he yelled. Surprise Surprise.
And, if you need more reasons, how about that it's a severe fire and emergency hazard? Ah, Temple Moor stupidity never ceases to amaze.