A Denizen's mind is not an understood construct, any more than a human being's mind is a fully understood construct - it is simply faithfully translated from a biological medium to a digital medium. As such, it takes skill and caution to tamper with it, though disconnected Denizen-brain is infinitely easier to reattach than disconnected pieces of brain from a biological human would be, and back-ups make the whole thing less terrifying than surgery on neural pathways would be.
The only person capable of altering a Denizen's mind are they themselves - or anyone that they give their private key to.
Autonomy and identity
A Denizen's autonomy and identity, both, are ensured by the Denizen's sole access to their private key. As such, the most reckless thing that a Denizen can do is to give their private key to someone else - and it has the same (if not worse) psychological connotations as signing oneself into slavery in real life would.
Sharing a copy of one's private key is nothing that can be done accidentally, secured by at least two confirmation dialogues, and in some cases by artificial delays and glaring reminders that passing on one's private key can mean anything from signing over life and health to the other user, all the way to losing all legal claim to one's resources or familial connections.