Who can setScope on networkView

I am using an authoritative server. One problem is that the server needs to send data to the owner of the player objects, but hide this data from other clients. I am trying to use NetworkView.SetScope so that other clients don't receive updates on the object.

However, if other clients can just change the scope so they receive updates, then they can cheat and lookup other player's data. Also, they could disable other players from receiving updates. Does only the owner of the networkView have the power to change the scope? Does only the server have the power to change the scope?

If scopes don't work, how can I prevent other players from receiving updates besides manually sending RPC calls?