Disgruntled employees have been the cause of many mass shootings over the years. Many years ago the inventor of the Barbecan portal licensed his first patent to a design firm based in Chicago. A week after visiting Chicago to meet with the managing director, newspaper headlines one day said "Designer goes berserk and shoots two…". The managing director was one of the two. While the shooting at the DC Navy Yard in 2013 can be considered a government building, in actuality it was essentially an office building requiring a key card to enter like many office buildings. Most commercial office buildings are also protected with key cards or keypads. That won’t deter a disgruntled employee or an attacker who has obtained legitimate entry credentials.