I don’t want to alarm you, but I fear there might be.It could be the fat guy sitting next to you. The mumbling one with the mustache. Or the thin, high-strung woman down the hall.Make no sudden movements, and edge casually towards the door.Ever since Edward Snowden blew the whistle on Uncle Sam’s secret intelligence apparatus, we’ve all been a bit jumpy about government surveillance. How big is it? How far does it go?