though this is a sad situation. When is this "workplace violence" going to end?
Never. It's human nature. As long as someone out there has been extremely offended and doesn't have the mental stops in place to prevent them from going postal, then this will keep happening. And it's not something we can stop without severely limiting certain freedoms that we currently enjoy.
The thing I always compare it to was my senior thesis back in high school - I was shocked to learn that we killed
40,000 Americans on US soil simply from
highway accidents, and the simple solution was to limit top speed to 20 MPH and make same-height bumpers mandatory - we'd hardly kill anyone that way! And if you combined that with stuff like Volvo's pedestrian avoidance system they have on their new cars, it'd be nearly zero. But, it would limit our ability to get from Point A to Point B in 5 minutes instead of 15 minutes, and the majority of people aren't willing to sacrifice that freedom. Like Heath Ledger's Joker said in Batman, people accept losses as long as it's all part of the plan. It's unfortunate, but that's how we operate. We could make self-driving cars for the cities and Elon Musk Hyperloop systems between the cities, but that would require (expensive) change and people are used to what we have now.
So as terrible as it is, I don't think we can ever 100% stop stuff like this. Despite all the stuff coming out about the NSA like Prism and all that jazz, people like the Boston Marathon bombers can still slip through the cracks and wreck havoc. And even if we could stop it, we'd end up with something like Minority Report, which opens up a whole new can of worms. I wish it wasn't that way, but I don't think anyone can offer a bulletproof system (no pun intended) for protecting people from this type of violence.