Maintain openness of Libraries for legitimate visitors

I noticed that a suggested change on one list was "increased security" by requiring IDs to use the library. While IDs are required to check materials out for the obvious reason of tracking the materials, I am strongly opposed to requiring them for anythin else.  Such a move would damage the atmosphere of openness that many of us at MIT cherish and would make life difficult for legitimate users of the libraries (visitors from other instututions or prospective students, for example).