It does not block proprietary scripts. It says that a page has no scripts, but a page has lots of proprietary js, and they are working. (I tried to create a bugreport with steps to reproduce on savannah.gnu.org, but the register page does not work lol) Also, librejs is VEEEEEERYYYY SLOOOOOOW, Firefox freezes for 20-30 seconds while librejs is trying to analyze scripts.