It's hard to talk about whether there is a problem or not when the people who receive (the national security letters) cannot talk about it.

Filters at public libraries are not the answer. Most filters out there are meant for home use. In a library setting, it doesn't work for a variety of reasons. It can be too restrictive or not restrictive enough. ... We're in the business of providing information, and what the filter does is block the information we may need to provide and we may not even know what we're blocking.