They are forcefully mobilised conscripts. If you get a mobilisation request in Russia you have two options: serve or go to jail. But since Russia is now sending prisoners to the battlefield, your two options are: serve or serve.

If you try organise a protest, you’ll be beaten up, go to jail and then sent to a battlefield. And if you manage to organise a very very big protest, everyone who participated will be shot dead by Rosgvardia. And don’t worry, Russia has centuries of experience of killing millions of protesters at once, so while it might be unimaginable in a Western country, it’s business as usual there.