It almost seems like a scaling thing at this point. If .1% of people will at some point commit a violent crime, at some scale you will have users that are in th

It almost seems like a scaling thing at this point. If .1% of people will at some point commit a violent crime, at some scale you will have users that are in that .1%. At 1,000 users, it's only one person. At 1m users, you've got a sizeable population. As an aside, I don't see much discussion surrounding the physical security (or lack of) at Youtube HQ. Not saying this could have been prevented, but most of my employers have had some form of card access system to limit the impact of events such as this.