The Russian military is freaking out right now because they use Telegram extensively.

If anything, Telegram's encryption is so sketchy, almost non-existent, that it may have been a Russian government honeypot pretending to be independent. Use of it is formally banned in the Ukrainian military, for damn good reasons. Almost all communication on Telegram is unencrypted.

It would have been much more reasonable to arrest him on the basis that Telegram was not private enough...