Well, for starters, to prevent the police from kicking my door in and shooting me or my pets simply because I was placed on a list of people who downloaded an app. Simply "police chase and abandon leads all the time" is not a strong enough rationale to justify the original suggestion to me.
I know the BLM astroturfing had a profound effect on the rest of the internet, but it’s disappointing to see such a skewed version of reality presented here on HN.
I just downloaded the app. Bring on the marauders. If they end up blasting me, you can start a charity in my honor, Vogt.
Looking back on the wording of my original reply, it was too hyperbolic. My post was not meant as an "ACAB, the police are literally here to kill you on behalf of rich old men". My position is that the fewer opportunities for folks to be thrown into a pile of suspects for the police or any other law enforcement institution like the FBI, the better. I'm in favor of the police being able to subpoena Apple and Google for user data if there's reasonable, articulable suspicion those users committed a crime. To me, simply downloading a publicly available app in the app store does not satisfy that condition.
If somebody in power wants to make a name for themselves by starting a "war on cat thieves" or similar you may face the same treatment.
Here's what I _would_ be in favor of:
-Police bust Catalyic Converter Kingpin in one form or another
-Police learn in the course of investigation that said kingpin was a prolific user of said app
-Police subpoena the usernames of accounts that corresponded directly with the kingpin
There's a compromise to be had here without throwing 50,000 into a digital suspect bin when maybe half were people actually complicit to...wait for it...a crime.