You're "allowed" to speak fairly freely, but there are unspoken laws about what you can and cannot say. The Cheka/mods can ban you/arrest you because they feel like it (and the mods don't even have an Article 58 to use!). It's all overseen by a mysterious figure no one knows much about.
To make it even more perfect, even the, ahem, proles are becoming aware of the risk of banning :\ Once you start punishing innocents out of fear for your state's integrity, you need to take a close look at your government.