For others saying something to the effect of "we let them search our X already, so the phone is a logical step and not a big deal," you've already given up your expectation of privacy, so you can't understand why others would want to keep it. This is the slow creep of the state with concomitant erosion of liberty.
In a few short years, you are the ones who will be justifying any of the following on grounds that "they already do the less-invasive thing, why not one step more?"
- Mandatory fingerprinting (USA does this for foreigners in some airports)
- Declare all cash, declare all crypto (with addresses / xpubs)
The Feds will already have most of this information now.
They've long had your bank account information (thanks to the PATRIOT Act). They probably have trackers installed on the chipsets of devices, but ignoring that, we know they are capable of intercepting most internet traffic.
Most people have their fingerprints taken, either as the result of a run-in with the law, legitimate or otherwise (clerical error). Or because they were incentivized in some manner (TSA Precheck). Federal IDs are rolling out now too.
In a few short years, you are the ones who will be justifying any of the following on grounds that "they already do the less-invasive thing, why not one step more?"
- Mandatory fingerprinting (USA does this for foreigners in some airports)
- Declare all cash, declare all crypto (with addresses / xpubs)
- Bank account logins
- Register electronic devices / install software trackers
- Hair sample for drug testing
- Cheek swab for DNA
- Blood draw to check for diseases / drugs / DNA