(CNN) Court documents unsealed Tuesday reveal the breadth of technical information federal investigators were permitted to collect on President Donald Trump's former fixer Michael Cohen.

Notably, the FBI made use of Cohen's use of Touch ID and Face ID on his Apple devices, which allow users to quickly log into iPhones and computers by scanning their face or fingerprint rather than typing in a password. Those features are marketed as faster and more secure ways to securely log into one's devices, as it's harder, though not impossible, to replicate someone's fingerprint or appearance.

But that gives law enforcement an additional means to access those devices. In one warrant application for Cohen, an FBI agent requested authorization "to press the fingers (including thumbs) of Cohen to the Touch ID sensors of the Subject Devices, or hold the Subject Devices in front of Cohen's face, for the purpose of attempting to unlock the Subject Devices via Touch ID or Face ID."

While the issue has never come before the Supreme Court, tech civil liberties experts warn that a warrant can compel a suspect to use their face or fingerprint to give up access to an otherwise locked device.

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