# Facebook Is Giving Advertisers Access to Your Shadow Contact Information

<https://gizmodo.com/facebook-is-giving-advertisers-access-to-your-shadow-co-1828476051>

- Host: [gizmodo.com](https://links.thingelstad.xyz/hosts/gizmodo.com/)
- Saved: September 27, 2018 (2018-09-28T01:42:49Z)
- Record: https://links.thingelstad.xyz/links/2c04d54a4477/
- JSON: https://links.thingelstad.xyz/links/2c04d54a4477.json

## What Jamie wrote

Another in the endless series of findings on how Facebook uses your data to target you. 

> I was helping him test the theory by targeting him in a way Facebook had previously told me wouldn’t work. I directed the ad to display to a Facebook account connected to the landline number for Alan Mislove’s office, a number Mislove has never provided to Facebook. He saw the ad within hours.

They are even doing this with data you give them for security purposes.

> They found that when a user gives Facebook a phone number for two-factor authentication or in order to receive alerts about new log-ins to a user’s account, that phone number became targetable by an advertiser within a couple of weeks.

The [EFF highlighted](https://www.eff.org/deeplinks/2018/09/you-gave-facebook-your-number-security-they-used-it-ads) this terrible use of security information for advertising targeting as well.

## Facts

- Kind: [Page](https://links.thingelstad.xyz/kinds/page/)

## Appears in

- [WT73: Weekly Thing #73 / Sep 29, 2018](https://weekly.thingelstad.com/archive/73/), Notable Links 📌

## Same host

- [How Facebook Figures Out Everyone You've Ever Met](https://links.thingelstad.xyz/links/0e9ece308384/) (gizmodo.com, November 10, 2017)
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- [Ring's Neighbors Data Let Us Map Amazon's Home Surveillance Network](https://links.thingelstad.xyz/links/144b55adc377/) (gizmodo.com, December 12, 2019)

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## Elsewhere

- Wayback Machine: https://web.archive.org/web/*/https://gizmodo.com/facebook-is-giving-advertisers-access-to-your-shadow-co-1828476051