First of all - add Israel. If you're a Gazan than this goes without saying, but even if you're a citizen, then - the General Security Service can and does people into custody without a warrant; often does not publicly disclose or admit said custody; and has "secret" detention facilities to hold such people (example: https://en.wikipedia.org/wiki/Camp_1391)

I also wonder about the US: What about the secret imprisonment mechanisms it set up after the 2001 attacks on the twin towers (9/11)? Were those ever dis-established?