I assumed at the time, and at the time of other similar busts, that US counterintelligence (mostly but probably not entirely the CIA), is aware of some number of persons doing illicit intelligence-gathering here. Whether, when, and whom to arrest and deport I take to depend on factors including whether our agents have been arrested, whether there is some other point we need to make, etc. I would not be surprised to learn that more than another ten Russian agents remained known or at least suspected, but unmolested for various reasons: to protect informants, to channel information or misinformation through them, or simply to have someone to arrest a few years down the road.