Hacker News Reader

Comment by cameldrv | Hacker News Reader

Slightly off topic, but Lyft has really creeped me out recently. The last three times I’ve landed at SFO, I’ve gotten a push notification on my iPhone from Lyft saying “welcome to SFO, get a Lyft.” It’s always come as we were taxiing to the gate.

After the first notification, I turned off location services for Lyft and only do one time authorizations, and then close the app when I’m done, but I still get the push notification. How is Lyft figuring out that I just landed at SFO? FWIW it has not happened at any other airport.

View on HN

There are many theories about this, but the one I find most plausible is that the airlines sell the data to Lyft.

Previous HN discussion here: https://news.ycombinator.com/item?id=43687696 Another forum discussion: https://archive.ph/wip/ck9CJ

Holy shit. I’ve also been similarly creeped out by this behavior as well, and did the same setting changes as the original commenter. This comment made me remember I signed up for a Delta/Lyft promo way back in college. In my case in explicitly signed up to link both accounts, but I wonder if they have other methods

My first thought was it could scan the WiFi names. I think there's many ways to determine location without GPS.

Apple restricts this as part of the location services permission though, and to clarify, it’s always happened very shortly after touchdown, just as we started to taxi, where probably the terminal WiFi is not in range.

After thinking about it more, I think they somehow know what flight I’m on and are using flightaware or a similar service to know when the plane touches down.

The question then is how they know I’m on the flight. They can do this if you share your calendar with them, but I don’t. The only thing I can think of is either the airline is selling them the data or they’re getting it from my credit card company. Airline flights are unusual on credit cards in that the entire itinerary is on your credit card statement, not just “American Airlines” or whatever.

I wonder if it uses Significant Location Change monitoring—which apparently works around “Always Allow” location permissions, and would be consistent with allowing location “once” or “while using the app” (which Lyft, I believe, requires as part of delivering its actual service). It also might explain why only SFO: is SFO one of your Apple-determined-and-enumerated “Significant Locations”?

https://developer.apple.com/documentation/corelocation/clloc...

(Edit: annoyingly, the parentheses are part of the URL. I don’t know how to encode them to make HN’s link parser happy, so you may have to add them by hand if you follow the link.)

(Edit 2: fixed, duh--thanks @akovaski!)

https://developer.apple.com/documentation/corelocation/clloc...

https://developer.mozilla.org/en-US/docs/Glossary/Percent-en...

I wouldn't assume this is how it works. But it could know your time zone changes and assume departure/arrival times based on it not being able to ping a server, then link this between possible airports based on time zones then possible flights based on the times.

But I suspect the false positives on this would be huge and if you felt so compelled could easily test while at your desk.

expanded receipt data is totally a thing, but then why would SFO be the only airport you've experienced this at? seems more likely there's something SFO is doing to see cell phone subscriber info, and selling that information to Lyft.

https://developer.apple.com/documentation/usernotifications/...

Yeah but it looks like it shouldn’t work in this case since the location permission wasn’t given:

> Before scheduling any notifications using this trigger, your app must have authorization to use Core Location and must have when-in-use permissions.

Reply on news.ycombinator.com