the security system on campus (while safe and effective) was considered a nuisance by the student population prior to a major overhaul which took effect in fall 2007. students (and residents) of boston university could not enter a dorm other than their own after 8 p.m. without being signed in, and were expected to leave the premises (unless allocated for a special study session, called a "study extension") by 2 a.m. study extensions allowed students who live on campus to remain in a dormitory other than their own until 7 a.m., at which time they were required to sign out of the building.