Are there other reasons? .........
Why act now?
"National Security" issues? Seems to be the Guv'mints reason to interfere with other liberties we think we have. Maybe they don't like all these planes flying around which they cannot force Mode-S into? Maybe TSA want to regulate overseas N-regs a bit and the CAA are being poodles. Or something similar.... Bl00dy hell, sound like some mad conspiracy theorist...