Handcuffs are being used by law enforcements to restrain criminals and possible suspects from using their hands, but it is also possible that criminals will use these type of handcuffs to restrain hostages.
We have done some research, and we found an awesome video which explains how it is possible to escape closed handcuffs by simply using a paper clip.
Please do note that it is illegal to perform this action if you have been handcuffed by police officers or other law enforcements organs. Just obey the law and like always – it is better to prevent these types of scenarios.