Do you have a link? Our Constitution is interpreted by the courts as allowing 72 hours to charge or release.
"The suspect, a former Philadelphia Police Department sergeant, has not been charged with any child porn crimes. Instead, he remains indefinitely imprisoned in Philadelphia's Federal Detention Center for refusing to unlock two drives encrypted with Apple's FileVault software in a case that once again highlights the extent to which the authorities are going to crack encrypted devices. The man is to remain jailed "until such time that he fully complies" with the decryption order."
He's not detained without charge. He's detained on the charge of contempt of court.