Seems this action in Russia fits precisely speculation of what could happen often posted against TSA threads here at FR.
It can, and will happen here too.
Exactly. Herd masses of people in long lines going through security, makes an easy target. Same thing happened in 1972 at Lod (now David Ben Gurion) Airport, in Tel Aviv, when terrorists shot and killed 26.
Yes indeed..it is coming no doubt. All they need is one inside person to open the gate...just one. If the economic conditions continue here I can see someone being paid lots of money to do just that.