It seems like it would be hard to make pronouncements about the error rate without knowing the actual rate of unsupportable requests? Moreover, you’re referencing FISA warrants which are so unlike typical warrants that constructing arguments based on FISA practice is risky.

Point me to an article if I’m wrong, but I haven’t heard even a single credible rumor that these Stingrays aren’t being used for exactly what authorities say they are - trying to find particular individuals is a general area. Have you heard of whistleblower accounts or accidentally leaked details about large scale storage ordata mining of location data from Stingrays?

If your argument is simply that law enforcement agencies don’t have the right to conduct a dragnet when pursuing a fugitive murderer, as is the case here, you’re going to need something more persuasive than a rant against authoritarianism.