Who decides what is needed?
The standard for keeping prisoners during war is the duration of the war plus 6 months, or upon an agreement between the warring sides.
The thing is, being a citizen doesn't come with guarentees of government protections at all. This is something we have come to expect only because our modern wars have been fought on foreign soil.
If the battlefields came home, would we be able to afford to grant every citizen their day in court for accusations of espionage, treason or just not getting out of the way quick enough?
Our freedoms and rights are great and should be respected, but if they become so rigid that our enemies can use them as a weapon against us, then we have already surrendered to them.