Noted where? There is nothing on this thread or any other thread (covering the subject of boric acid) that would indicate even one single practical use for it by terrorists. I could make a more dangerous weapon out of dry-ice and 2 liter plastic coke bottles, than I could with boric acid.
--Boot Hill
Here is one possible use for your consideration:
amorphous boron is used in pyrotechnic flares (distinctive green colour), and rockets (as an igniter)