This is deeply disturbing.
I guaran-damn-tee you, this method will be tried in this country in specific situations. It probably already is for a few unlucky dozens. Not everything gets talked about on the internet while it’s happening.
One’s phone can be taken away for some made up reason. We see with those imprisioned over the Jan 6th ‘crimes’, that you may or may not receive a speedy trial. You may or may not receive legal representation for your trial. You may or may not receive adaquate medical care during your incarceration.
The phones will be taken away to hide the coming brutality. This is the early phase of gulag 101. Once the ability to hide all their actions is complete you will see Soviet style nasty.