Because we're not talking about human beings. We're talking about huge, huge collectives of humans that are impossible to trust or predict. Think of states like

Because we're not talking about human beings. We're talking about huge, huge collectives of humans that are impossible to trust or predict. Think of states like you do of corproations: You wouldn't trust a corporation to do "the right thing" or "act nice", wouldn't you? Now image the corporation has nukes and tanks and lives next to your back door. We have a saying: "Trust is nice, surveillance is better" (which is used in different context but applies very nicely for this situation).