5 ms·

>Facebook reads the accelerometer all the time. Facebook actually shows a support prompt if a shake event is detected across the app. This could be one reason w

>Facebook reads the accelerometer all the time. Facebook actually shows a support prompt if a shake event is detected across the app. This could be one reason why Facebook reads accelerometer data. No. Shake gestures are handled at the OS level and you only get began/changed/ended callbacks. Raw accelerometer data requires the CoreMotion framework, and it’s a lower level API. They are definitely using it for something else. This is also confirmed by this: >The prompt has an option to switch this feature off. However, switching it off doesn’t stop the app from reading the accelerometer.

jbverschoor 5y ago
Well it's handy to know if your phone is being held, in the car, on your desk. You can 'track' if someone glanced at notifications, doing a spaced-repetition type delay between glances. Or maybe you want notification when you're looking at your phone (certain angle and shakeyness). Or maybe when you're on the phone (different angle).
RicoElectrico 5y ago
> They are definitely using it for something else. Like 3D and 360 photos.
- moffkalast 5y ago
  You'd need the gyro for that, more like.
- jonplackett 5y ago
  If they were really only using it for this, it would only activate when viewing them. It's good practice to only activate the accelerometer when in use because it uses up battery.
  - jtbayly 5y ago
    It uses essentially no battery. IIRC, it uses so little that even when your phone battery runs out and the phone turns off, the accelerometer keeps counting your steps.
    - skohan 5y ago
      But constantly recording it and phoning home might be using significant battery
      - InitialLastName 5y ago
        If apps were worried that phoning home with the data they recorded used significant battery, we might be in a different position in terms of how frequently they do it.
      - spicybright 5y ago
        Meh, not if you store everything then bulk send it later.
    - chrisshroba 5y ago
      Wow really? Do you have a source on that?
      - magicalhippo 5y ago
        Several such "motion chips" have onboard motion processing. As a random example the MPU-9250[1], a 9-DOF IMU, has a low-power pedometer feature which can keep step count while host processor sleeps or is offline. [1]: https://product.tdk.com/en/search/sensor/mortion-inertial/imu/info?part_no=MPU-9250 https://product.tdk.com/en/search/sensor/mortion-inertial/im...
        floatboth 5y ago
        Even without onboard processing it's a very obvious move to offload it to a tiny microcontroller. Apple actually started by using a physically separate NXP micro that they branded "M7". Now it is of course on the main chip, but still a separate Cortex-M core.
      - jtbayly 5y ago
        This is old. Could have changed since then, but here you go: https://www.dailymail.co.uk/sciencetech/article-2573761/amp/Apple-track-AFTER-iPhone-battery-dies-Sensors-continue-collect-data-phone-dead.html https://www.dailymail.co.uk/sciencetech/article-2573761/amp/...
  - hbn 5y ago
    It can't be that intensive considering Apple's done that parallax homescreen effect since like iOS7. Also when you're in the Safari tab overview, it reads the gyroscope to do a 3D effect where the tabs tilt forwards/backwards. Probably a few other areas I'm not thinking of too.
  - thrwyoilarticle 5y ago
    The Facebook apps and websites are full of bugs, bad code, bad practices.
dilippkumar 5y ago
I've heard unreliable and whispered rumors (from the tech grapevine) that the accelerometer was a bot-farm mitigation strategy. The idea is that a bot farm with thousands of phones on racks won't have some signature that the accelerometer should see when the screen is tapped (for example, when typing a message or hitting a like button). I happen to believe this theory.
- nimih 5y ago
  It's probably being used for multiple purposes, regardless of the original intent. Recall that FB originally collected phone numbers for 2FA, but years later decided to use the information for ad targeting[1]. Not that Facebook is unique in this regard, of course; my own experience at companies which collect various bits and pieces of customer data is that, once the data is in a database somewhere, people are pretty good at finding excuses to use it. [1] https://www.impactplus.com/blog/facebooks-using-2fa-phone-numbers-for-ad-targeting https://www.impactplus.com/blog/facebooks-using-2fa-phone-nu...
- RandallBrown 5y ago
  It's been a few years but I do recall adding a framework that claimed to use the accelerometer to help with bot detection. I believe it was PerimeterX.

jbverschoor 5y ago

Well it's handy to know if your phone is being held, in the car, on your desk. You can 'track' if someone glanced at notifications, doing a spaced-repetition type delay between glances. Or maybe you want notification when you're looking at your phone (certain angle and shakeyness). Or maybe when you're on the phone (different angle).

RicoElectrico 5y ago

> They are definitely using it for something else. Like 3D and 360 photos.

moffkalast 5y ago
You'd need the gyro for that, more like.
jonplackett 5y ago
If they were really only using it for this, it would only activate when viewing them. It's good practice to only activate the accelerometer when in use because it uses up battery.
- jtbayly 5y ago
  It uses essentially no battery. IIRC, it uses so little that even when your phone battery runs out and the phone turns off, the accelerometer keeps counting your steps.
  - skohan 5y ago
    But constantly recording it and phoning home might be using significant battery
    - InitialLastName 5y ago
      If apps were worried that phoning home with the data they recorded used significant battery, we might be in a different position in terms of how frequently they do it.
    - spicybright 5y ago
      Meh, not if you store everything then bulk send it later.
  - chrisshroba 5y ago
    Wow really? Do you have a source on that?
    - magicalhippo 5y ago
      Several such "motion chips" have onboard motion processing. As a random example the MPU-9250[1], a 9-DOF IMU, has a low-power pedometer feature which can keep step count while host processor sleeps or is offline. [1]: https://product.tdk.com/en/search/sensor/mortion-inertial/imu/info?part_no=MPU-9250 https://product.tdk.com/en/search/sensor/mortion-inertial/im...
      - floatboth 5y ago
        Even without onboard processing it's a very obvious move to offload it to a tiny microcontroller. Apple actually started by using a physically separate NXP micro that they branded "M7". Now it is of course on the main chip, but still a separate Cortex-M core.
    - jtbayly 5y ago
      This is old. Could have changed since then, but here you go: https://www.dailymail.co.uk/sciencetech/article-2573761/amp/Apple-track-AFTER-iPhone-battery-dies-Sensors-continue-collect-data-phone-dead.html https://www.dailymail.co.uk/sciencetech/article-2573761/amp/...
- hbn 5y ago
  It can't be that intensive considering Apple's done that parallax homescreen effect since like iOS7. Also when you're in the Safari tab overview, it reads the gyroscope to do a 3D effect where the tabs tilt forwards/backwards. Probably a few other areas I'm not thinking of too.
- thrwyoilarticle 5y ago
  The Facebook apps and websites are full of bugs, bad code, bad practices.

dilippkumar 5y ago

I've heard unreliable and whispered rumors (from the tech grapevine) that the accelerometer was a bot-farm mitigation strategy. The idea is that a bot farm with thousands of phones on racks won't have some signature that the accelerometer should see when the screen is tapped (for example, when typing a message or hitting a like button). I happen to believe this theory.

nimih 5y ago
It's probably being used for multiple purposes, regardless of the original intent. Recall that FB originally collected phone numbers for 2FA, but years later decided to use the information for ad targeting[1]. Not that Facebook is unique in this regard, of course; my own experience at companies which collect various bits and pieces of customer data is that, once the data is in a database somewhere, people are pretty good at finding excuses to use it. [1] https://www.impactplus.com/blog/facebooks-using-2fa-phone-numbers-for-ad-targeting https://www.impactplus.com/blog/facebooks-using-2fa-phone-nu...
RandallBrown 5y ago
It's been a few years but I do recall adding a framework that claimed to use the accelerometer to help with bot detection. I believe it was PerimeterX.