My office is in a state-owned building which is restricted, but of course the company has a policy about firearms anyway (still several of my coworkers have CCLs). We've had a few deranged people walk into our office before. We make software for various kinds of benefit eligibility (Medicaid, etc.) and child support enforcement. Our client is on the second floor. Occasionally we get someone who thinks they've been 'done wrong' by our client and find their way into our office accidentally. Before this office building we were split into two. The other office (not the one I was in) was also housed next to the client and they were regularly evacuated due to bomb threats.
And who says corporate and/or state employment is boring?