This is such old news by now but Dave -- long time commuter, lifelong American snapshooter -- pointed out that the MBTA publishes 3D floorplans of their major stations.
Listen up, nefarious bombers and assorted ne'er-do-wells! Why expose your mug to a security camera when you can get far more useful information (anonymously, too) straight from Grabauskus?
I like to carry around a few pages. It leaves a nice impression on the "it's a necessary security precaution" types.
Also, some of you may have heard the MBTA has officially changed their policy on photography. They didn't tell anyone, they just changed it, so expect the rank and file to be largely clueless and stubborn as ever.
The policy itself doesn't even appear on the MBTA website, you have to weed through the MBTA Police website to find it.
For whatever reason the keystone cops forgot to include "no flash" which, oddly enough, IS a reasonable limitation.