This article from the BBC today implies that the Russian generals are being
targeted based on cell phone calls, among other things. If true, they're
ignorant of cellphone technology.
Fourth Russian general killed - Zelensky
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https://www.bbc.com/news/world-europe-60767664>
"For Ukraine to target specific Russian officers, it needs to know where
they are. Analysts say that Russia has been using open channels of
communications which could give clues about where certain targets are
located.
"If the Russians are using mobile phones or analogue radios to communicate
with senior officers, the Ukrainians have everything on their plate,"
defence analyst Konrad Muzyka of Rochan Consulting told the BBC."
After the death of another senior officer - Maj Gen Vitaly Gerasimov -
Ukraine released a recording purporting to be two Russian security officers
discussing the general's death, and complaining that their secure
communications network was not working.