It's not new, they always use cell phones, also "even" officers for battlefield comms.
What the Russian military quite successfully cracked on is soldiers taking selfies everywhere to post in VKontakte as there's remarkably little of it going on.
Some/many units also even execute every Ukrainian civilian caught taking photos of their positions of they're caught with such photos on their phones to keep opsec and don't get arty on their location. It's not a paranoia from their side because it's how it works actually.
It's not new, they always use cell phones, also "even" officers for battlefield comms.
What the Russian military quite successfully cracked on is soldiers taking selfies everywhere to post in VKontakte as there's remarkably little of it going on.
Some/many units also even execute every Ukrainian civilian caught taking photos of their positions of they're caught with such photos on their phones to keep opsec and don't get arty on their location. It's not a paranoia from their side because it's how it works actually.