Embassies are full of secret spying equipment, and indeed spies. Foreign warships that come to visit "interesting" ports have been known to carry extra electronics intelligence equipment.
My point was that you don't have to imagine a foreign power having unknown surveillance equipment on your nation's soil. Unless you're in the most backwater nation on earth foreign powers will already be doing this.
My point was that you don't have to imagine a foreign power having unknown surveillance equipment on your nation's soil. Unless you're in the most backwater nation on earth foreign powers will already be doing this.