The Russian [former Soviet] embassy in Washington is a primary location for Russian [and Soviet] intelligence operations in the United States. In addition to technical facilities for monitoring American communications in the Washington area, it has been the locale for numerous unsolicited "walk-in" recruitments of Americans.
The embassy is closely monitored by counter-intelligence agents from the FBI Washington Field Office, who may be operating from this building across the street from the Russian embassy. All phone calls to the Russian embassy are monitored by the FBI for counter-intelligence purposes.