Compelling your fingerprint isn't considered unlawful search

[Isgrimnur]

The Register

An Illinois judge has rejected a warrant sought by the US government to force everyone in a given location to apply his or her fingerprints to any Apple electronic device investigators happen to find there, a ruling contrary to a similar warrant request granted last year by a judge in California.

Under current law, the government already has the right, given sufficient evidence, to compel a specific individual to unlock an electronic device protected by a fingerprint reader like Apple's Touch ID sensor.

In 2014, a judge on Virginia’s Second Judicial Circuit ruled that a defendant could be forced to provide a fingerprint but not a passcode, the distinction being that a fingerprint is not testimonial whereas a passcode is.

Defendants thus cannot use the Fifth Amendment's protection to refuse to provide a fingerprint on the grounds that the fingerprint itself qualifies as self-incriminating testimony.
...
Essentially, prosecutors want to go into a vaguely described location – perhaps a home or an office – and make every inside, regardless of who they are, provide their fingerprints to unlock their Apple handhelds so investigators can rifle through the devices for evidence. The warrant doesn't say where this raid will take place nor exactly who is targeted.

The government's cause in Illinois may be easy to support – the warrant is part of an investigation involving the sexual abuse of multiple victims by someone associated with the premises in question and the trafficking in child pornography over the associated internet connection. But its methods present legal issues that go beyond this specific case.

The judge accepts that the Fourth Amendment – which protects against unreasonable searches and seizures by the government – does not protect fingerprints.

But in this case, the judge wrote in his order, "the government is seeking the authority to seize any individual at the subject premises and force the application of their [sic] fingerprints as directed by government agents."

[Jolor]

Counterpoint: You are within your rights to refuse this. In fact, every time I do, I'm thanked with a lovely glass of cool, refreshing water. Know your rights! You will be respected for it!