Christian Briggs posted this as his sound theme for 2010, noting how music from the Amok time fight scene in Star Trek played in his head as he rapidly calculated how to best discourage a violent encounter with someone "a few fries short of a happy meal" on the first morning of the new year. ("Before coffee," no less.)
A PhD candidate in Human-Computer Interaction Design and Complex Systems at Indiana University (and co-founder of Social Lens, a research and advisory group), Briggs then wrote a Public Service Announcement on Home Invasions about the experience. It contains sage advice about deterring encounters of the unwelcome kind – you can find it at the link. Read it and maybe rethink those open doors.