Earlier quoted context omitted.
The Eastern Bloc had plenty of terrorism, as well as organized crime -- who do you think was supplying all those black markets? Being a police state is one thing; being an _effective_ police state is something else, much harder (at least in the pre-computer era). In the Soviet case, it didn't help that they didn't really care much about crime...
Plenty of terrorism? USSR funded and commited plenty of terrorism, but I've yet to hear of any terrorist incidents prior to the perestroila.. Soviets did have some organized crime, but they were well, Russians. GDR, Czechoslovakia, etc, somewhat less inept countries had very little crime and no organized crime to speak of.
While the regime exercised strong control of information prior to glasnost, and had plenty of motive to repress information that would indicate weakness of the regime, there are numerous known hijackings, the 1977 Moscow bombings, and others. (While reliable information about responsibility for some, and any broader organizational responsibility that might be behind those clearly responsible for others, is hard to come by, there does seem to be a disproportionate link to Armenia among the known incidents, with some specifically linked to Armenian nationalists.)