Librarians take note: Filtering is a collection development issue. Excellent article.
Don't get me started on libraries and email.
Email is a form of communication. We don't tell library patrons that they are more than welcome to use our phones or our FAX machines. Nor do we hand out free postage stamps to ptrons.
Hence, I do not believe libraries should offer email to patrons, either.
Unclutter worries from your mind
1 hour ago