Even worse than 1234?
http://www.nrk.no/troms/kvinne-kan-bli-tvunget-til-a-apne-telefonen-med-fingeravtrykk-1.12723383
While awaiting a final decision on the above, another case appeared outside Bergen (Norway), where a lower court allowed the police to use force (…) to unlock a fingerprint protected phone in their chase for evidence:
http://www.ba.no/nyheter/politi/kriminalitet-og-rettsvesen/politiet-far-tvinge-27-arings-tommel-ned-pa-mobilen/s/5-8-274391
US courts have already ruled http://www.wired.com/2013/09/the-unexpected-result-of-fingerprint-authentication-that-you-cant-take-the-fifth/ and http://www.macrumors.com/2014/10/31/fingerprints-not-protected-by-fifth-amendment/) that individuals cannot invoke the fifth amendment in this context, as the police have the right to collect all fingerprints, and using those prints to unlock any fingerprint device a person may have is not a violation of the fifth amendment («no person shall be compelled in any criminal case to be a witness against himself»). At the time being this applies to fingerprints specifically, and the future will eventually show whether other biometric authentication schemes may become subject to the same type of ruling. A pin or password on the other hand is protected equally in Norway as in the US — individuals have the right to remain silent, and a password can be forgotten.
While the use of 2-step verification / 2-factor authentication remains strongly recommended, there is little doubt that biometrics as a single factor should be considered less secure than even the simplest of 4-digit pin codes for physical access to a device.
The way fingerprint ID is implemented into smartphones and tablets today, they essentially work as a time-limited 2SV solution, where users identify by pin/password at boot, and then use a fingerprint as 1FA for ease of access to their device. This leaves a time-limited window of opportunity for forced access using a fingerprint, which is a new risk in addition to other forensics access tricks.
Any counterarguments?