Totally Natural.

I can even name systems which are extremely "popular". 

Western countries are attempting to steal Moscow’s military technology and are targeting industry experts, Russian Industry and Trade Minister Denis Manturov said on Monday. During an interview with news agency RIA Novosti, Manturov was asked if there were instances of industrial espionage by “unfriendly countries” while Russia is ramping up defense production. “This has been the case at all times. It is occurring today and will occur tomorrow,” the minister said. “There is an active hunt not only for promising research, the data and parameters of our weapons, but also for our specialists who are especially valuable.” “It is not only the issue of espionage. I believe you’ve seen media reports that the FSB had prevented an attempt on the life of one of top managers of a defense company,” the minister said.

It is totally expected and they salivate at anything hypersonic, S-350, 400, 300V4 line of AD complexes, and a variety of munitions, not least for new generation of Krasnopol which is now in serial production and is already being used on the front-lines. And this is just a very short list, with standoff weaponry being another hot commodity. Per engineers? Too late, most of them are deeply rooted in Russia, make a very good living and, naturally, are both protected and tracked by FSB. The West, however, is more than welcome to take economists, political scientists and "experts" with degrees from most "prestigious" schools in Russia. I would start from VShE. While at it, there are also many "free thinkers" of other caliber and because most of them can hardly qualify for sweeping the streets of Russian cities, they will fit perfectly with Western academe. 

But seriously, the hunt for Russian military (and not only) technologies will not only continue, it will increase dramatically because in terms of military and some dual use technologies Russia is way ahead of the combined West and the gap grows. War does it to you--most of the time you leapfrog in combat technologies and many civilian applications which follow. In related news--attack on port Feodosia. All kinds of Ukie and Western outlets report that they "destroyed" a landing ship Novocherkassk. Could be true, but as was the case with THREE (in reality--zero) Su-34, let's wait and see what will Russian side say. Novocherkassk is an old pr. 775 landing ship built in Poland in 1987 and if it was there in repairs, possible that she sustained the damage. We'll see. As you may expect, the response will follow. Ukies are mourning the loss of Mariinka and, as is traditional now, needed some PR action to raise spirits. Wrong way to do it. Especially when two IRIS-M complexes have been taken out in the last 48 hours.