Comment by simplyluke
16 hours ago
> your CC payments help track
Not only that. Them and the point-of-sale vendors (aptly shortened PoS), sell that data. They tend to attempt to do this anonymized. How successful they are in anonymizing that is very much so up for debate.
The websites (and even their retail locations) you buy from send your purchase data to meta and other advertisers directly via APIs so they can better track their marketing conversion rates. You can browse their APIs [1][2] to see what kind of data they like to get, but it tends to be every piece of identification they have on you. Rewards programs make this a much richer data set. You don't need to be a user of Google/Meta for them to build a marketing profile based on this. Google links your physical conversion from ads based on your maps data. Facebook does the same if you give them your location data. Many retailers attempt to use the bluetooth/wifi signals from your phone to track the same data even if you pay in cash [3].
There's no legal framework preventing this outside of the EU and California.
1: https://developers.facebook.com/documentation/ads-commerce/c... 2: https://developers.google.com/google-ads/api/docs/conversion... 3: https://www.nytimes.com/interactive/2019/06/14/opinion/bluet...
> They tend to attempt to do this anonymized. How successful they are in anonymizing that is very much so up for debate.
Yeah I think the big thing to push or talk about is that there is no such thing as "anonymized".
There's only such as a thing as "can only be identified as X many people". Like for a given dataset you can make any data point correlated to 1 of say 50 people. If somebody is anonymizing data and they don't provide a k-anonmizity [1] you should just assume it's 1:1 and effectively not anonmized.
[1]: https://en.wikipedia.org/wiki/K-anonymity
K-Anonymity isn't the only technique. Differential Privacy is arguably more robust.
> They tend to attempt to do this anonymized. How successful they are in anonymizing that is very much so up for debate.
In the good old days, if you were found to be informing on your neighbors to hostile powers, you were liable to find yourself in a mass grave when the political winds shifted, or even sooner.
But now it's so convenient and discreet and common, we think nothing of it. Plus, Google and Apple and Facebook and their partners and everyone they sell data to are our friends, not enemies :)