[snogglethorpe]

I used to do research at the local branch of some official government research library, and they were very strict about enforcing such limits; they kept track of who copied what, how much, and when. They did not lend, and if the limit was six pages and you wanted to copy seven pages you were out of luck... [there was some timeout, so you could come back some days later and copy the remaining pages, but man was it ever a pain...]

If you asked them why, they were decent enough to provide some sort of reasoned argument based on the actual copyright law to explain this policy, so I don't think they were just being jerks.

[This was in the UK, so I dunno if the laws were worse or better than in the U.S.]