[zlatan_todoric]

Not all answer need to be pure technical ones - they don't go and search person by person via manpower but they use meta data and algorithms. Simple overflowing their meta data would force them to use other means. Also you forget social impact - if majority of people actually listened to RMS that means majority of people would be very privacy and security minded and would press the government to change the laws (NSA spying is illegal anyway but with majority of folks actually actively pursuing this would made their existence hard or at least not possible to just go and spy and ruing privacy of entire planet).