Access control is perhaps another issue that comes into play for any system. As journal commenting systems have proven, most researchers are hesitant, if not downright hostile, to the idea of publicly commenting on the works of others. Most researchers do discuss works in smaller, trusted, private groups like within a lab or at a journal club. Useful annotation systems may need to offer the ability to make comments completely personal, privately shared or public.

[comment by David Crotty]