I live in the Bay Area and I could definately see this happening. Bart goes straight into the terminal of SFO, and is currently in construction to go into Oakland Airport. When you enter a bart train, it's very similar to entering a sports venue. A B-220 could definately be installed at the point of a ticket going through. But, here's the best news. In 2012, a new state of the art security forum called Vigilant Solutions Forms Advisory, formed in near by Livermore. I could go on and on about the area and government facilities, security, etc. but, this group is known as the go to force for security solutions. Two of the four founding members of the advisory? Howard Safir, and Robert Liscowski, both on the board of directors for implant sciences.