Prosecutors would need to be able to defend every element they use to gather evidence in court. Nothing downstream from inadmissible evidence can be admissible in court. “Fruit of the poisonous tree.”
No. Actually, that’s not true. If you upscaled a picture of a drug deal and then used that to narrow your search set and then posted a watch on that set to catch them dealing drugs, you’ve got a useful case. Totally admissible.