Here we go! You knew it was coming.
Wait what... you didn't know?
Well, as the title says, police in Michigan, and presumably elsewhere, have now begun to unlock phones by 3D printing the fingerprints of "criminals". The original report by Rose Eveleth of Fusion, goes on to clarify that police approached a lab to recreate the prints of a "dead man".
To be fair, this has probably been going on for a while
Now, while this was a "dead man" and many states claim that at this point, they can access the credentials of said person for investigative reasons. If the process was used for more undercover processes, you wouldn't be likely to hear about it. However, with that "weapon" in their arsenal, you better believe it'll be used when and where needed.
They probably already have your fingerprints
BTW, do you remember those required fingerprints you had to give when renewing your driver's license? You don't remember? Well, most states in the US require it now and have been for years. There is a strong chance that your fingerprints are already on file with your local state, and therefore the federal government.
So, next time the police want to get data off your phone, they can go print their access.
In a response to this, and previous claims, Apple has released a security update that requires the pass code be input if the phone is idle for more than 48 hours, as well as a few other pass code requirements.
It works
In case you're skeptical of the ability to successfully do this, many videos have been done demonstrating how since the release of the iPhone 6 and the fingerprint scanning feature. This video below was made back at the end of 2014.
What can you do?
Aside from not using the fingerprint feature, not much. 48 hours might help in some cases, but if the police, or anyone for that matter, are trying to access your phone for undercover reasons, it won't be happening after 48 hours.
The truth is, there isn't much you can do here to protect yourself against this particular case. Unfortunately, your phone isn't very secure in general. But, the fingerprint scanning feature might be one of the simplest back doors on your device.
Godspeed!