The professors who don't care are the ones who actually change their tests every year, or whose tests are more essay/conceptual than multiple choice. The ones who do, like to reuse tests either for ease or because they're good tests.

This is probably why law students are encouraged to look things up, their tests are more - I assume - concept/essay/short answer based rather than ABCD

I'm sure that nowadays if someone wanted to make an ongoing "Football Players Test Bank" or "Bullwinkle Hall Test Bank" it could be done extremely easily online. Greeks thought it up first and had the easiest place to put it in...if no one else can think of a way to do the same thing, it's not the GLOs' fault that they are stupid.

As a teacher (granted, not in college) I don't mind if people are sharing old tests for two simple reasons:
1. I change them all the time. Yes, some questions may repeat two years in a row but if you want to memorize all the questions on the off chance it will show again then you may get a few points here and there. But...
2. All semester exams have new material. So you may score high on the regular tests, but the semester exam which counts for 30% of your grade you are screwed.
In my opinion, looking at previous tests just helps understand how the teacher marks as you may have a great idea of the content but if you can't word it correctly, you are missing out.

That being said, there are some professors/departments who look down on it. I vaguely remember one of my professors arguing it was his "intellectual property" or some crap like that and another who said if we knew anyone who had tests and we could produce that test and name the person (for some kind of academic honesty change), we would get an automatic A in the class. And in the course, I would have sold out my grandmother for an A...and I'm sure many others would have too.

My college had all of old tests available to every student who could be bothered to go to the faculty library and get them out