It just seems like you could not legally stop everybody entering a particular area and pull identifying data off their phone, so why is it legal to do a blanket search of an area with a cell provider to get the identifiers of all those who entered that same areaAt least there's one person left that still has faith in the justice system. We never thought phony FISA warrants could be issued to spy on a presidential candidate but here we are, imagine what they would do to some peon. If things are still okay at the local level at least that's something.
At a guess, I would suspect it is easier to get the provider to roll over on their customers (provided the warrant is sealed) whereas pushback from among the many individuals is almost guaranteed. The solution would seem to be to limit the sealing of such a warrant. That it was made public before the investigation was completed could be answered with admonition to LE that this type of warrant should be limited to a mature investigation and those caught up in the warrant should be able to find out about it and sue the provider