This is small potatoes compared to the number of apps out there periodically harvesting a users' locations to be aggregated and sold to some quant fund.
Stalking can present real, immediate, and severe consequences to the target(s).
What do you mean to imply?
I don't give a damn that my data is anonymized, aggregated, and sold to some asshole on Wall Street, who uses it to make a stock trade. Even if it's not anonymized well, this is not a physical threat to my safety, because the people buying the data don't care about me. I'm not special. And they don't care about hurting me - they just want to make stock trades.
I mean, I care about this sort of thing - but I care only a little.
I sure as hell care that someone might be using the information on my phone to physically stalk me, in particular. The latter is an active threat to my life and limb.
It's much more difficult to take back your privacy than it is to maintain it in the first place.
Let's not pretend that the threat profile between those two things is remotely similar. Just because it's a gradient, with grey areas in between, doesn't mean that the two situations aren't entirely different. I may not be able to tell you when black turns to gray, and gray turns to white, but I am pretty sure I shouldn't believe anyone who is trying to tell me that black is white.
It takes being incredibly secure in your physical safety to equate "Some investment firm buys my phone's data" and "Someone is physically stalking me."
It's the difference between me knowing that your house exists in a land registry... somewhere - and me physically following you to your home, and waiting outside as you go to sleep. You shouldn't lose much sleep over the former.
A teacher doesn't have a real incentive to hand off your child to a stranger.
A company holding a large amount of user data has the opportunity to make millions or billions of dollars if they are allowed to sell it as they please. And they would likely do everything in their power to do so if they thought they could get away with it. That is why I think it's such a slippery slope that we should avoid all together.