> There's certainly a plausible Kremlin long con here

Not very plausible if compared to other things Kremlin does. Too long, too complicated, too hollywood. The modus operandi is much simpler - you do not need complex cons if you control everything. If you can come to Yandex and demand any data you want, anytime. You just have to keep Yandex alive, they'll find a way to get data (because it's their lifeblood, they are a data organization company, like Google) and when they do, you get the data too. Simple.