In cryptography, rubber-hose cryptanalysis means the extraction of cryptographic secrets (e.g. the password to an encrypted file) from a person by coercion or torture (as opposed to using a mathematical or technical cryptanalytic attack) — such as beating that person with a rubber hose.
Several countries in the world routinely torture people (as per Amnesty International and the UN) so its logical to assume that at least some of those countries use (or would be willing to use) some form of rubber-hose cryptanalysis.
In practice, psychological coercion can prove as effective as physical torture. Not physically violent but highly intimidating methods include such tactics as the threat of harsh legal penalties. The incentive to cooperate may be some form of plea bargain, such as an offer to drop or reduce criminal charges against a suspect in return for full co-operation with investigators. Alternatively, in some countries threats may be made to prosecute as co-conspirators (or inflict violence upon) close relatives (e.g. spouse, children, or parents) of the person being questioned unless they co-operate.
Rubber hose cryptanalysis, are often the easiest way to defeat cryptography.
Neuroscience Meets Cryptography: Designing Crypto Primitives Secure Against Rubber Hose Attacks