Should Libraries impose limits on interlibrary loan requests?

Do any universities have policies limiting the number of interlibrary loans that a student or faculty member requests over a period of time?

Over the years the university has grown by offering new programs, but funding for the library has remained flat. The growth in interlibrary loan requests is a result of the libraries inability to provide resources in these new areas. Our interlibrary loan staff reports some very heavy requesters. It is impossible to tell how important an article or book is for a patron. Very often a paper is essential since a researcher may need to repeat an experiment reported in the literature. Sometimes, an article is needed for current awareness. In this case reading the abstract may be sufficient.

Limiting the number of requests may hinder a researcher, but if an interlibrary loan office is bogged down by some frequent requesters, other patrons may have to wait.

Any comments?