We are taking about a random local cop here, not the NSA.
You obviously haven't heard about parallel construction (or evidence laundering)....
Yes this is the weird part. Since this activity was always voluntary, I wonder about the real reason for this policy change.
Going to a judge for a warrant is not a "secret law." The intelligence community is legally barred from collecting on US persons anyway, and they also DGAF about petty crime, because they have more important national security-related fish to fry.
> The intelligence community is legally barred from collecting on US persons
Only for their made-up definition of the word "collecting", which in some cases is "retrieving the data which we have already collected and stored".