This may be nothing but urban legend, but if I recall correctly this won't be the first time that Russia, or in this case, the old Soviet Union has sought retribution for attacks against their diplomats.
It seems that some time during the 1980's that some members of one of the many groups vying fro control of Lebanon kidnapped and killed one or more members of the Soviet embassy in Beirut. Legend has it that the KGB tracked down the perpetrators and their families, then killed and dismembered them all, leaving the remains where they would be found. It was a message that terrorist organizations and their supporters understood loud and clear:
Kill our diplomats and we will kill you and your families. Don't screw with us.
After that, everybody left the Soviets alone.
I wonder if this will be a lesson the Russians will teach these Islamofascist Pinheads...again?