(a) and (b) and (d) you can certainly control if you're not in an area with ubiquitous license plate readers. Anybody who isn't a rank amateur is going to assu

(a) and (b) and (d) you can certainly control if you're not in an area with ubiquitous license plate readers. Anybody who isn't a rank amateur is going to assume his communications are or will be scrutinized. Hell, even the "good guys" who handle classified information are taught to assume public communications channels are compromised. (c) you might have a harder time coping with, but people have to suspect you before they'll try to piece together those kinds of records. And even then... Robert Hanson got away with it for decades using dead drops in public places. You need a whole lot of information before you can tell the difference between a day at the beach and a day at the beach where a potential spy passed classified information to someone. I would bet my last dollar the vast majority of spies are compromised by enemy agents in their own intelligence network. No matter how good you are, if your boss is working for the enemy you're going to get caught. Indeed, Philby himself was outed by a KGB agent who defected to the West.