I read somewhere couple of years ago the entire Capitol hill is bugged and they literally have tear down the whole place to get rid of them. The bugs have been planted over years, some inside curtain rods, wood paneling and electrical equipment.
I've met Russians, Ukranians and Belarussians on a number of occassions in the SF Bay Area who's demeanor, attitudes and sketchy backgrounds indicate they are likely spies gradually increasing their foothold through businesses, startups and contacts in American military/aerospace industrial complex.