Thank you for reposting this. I had forgotten how good a write up it was, and also just what social commentary about de-anonymization it is. The relevant part

Thank you for reposting this. I had forgotten how good a write up it was, and also just what social commentary about de-anonymization it is. The relevant part for that is right here: > EDIT: Facebook has since changed its policies and won’t allow you to market to any audience with less than 20 people. If you want to try this yourself, there’s a loophole. Let’s say you want to target one of your guy friends, add his email to a .CSV along with the emails of 19 female friends before uploading it to Facebook. You can then target anyone in that custom audience who is also male (thus eliminating the 19 women and effectively targeting a single person). This is the problem with audience segmentation. While there has been a lot of emphasis on protecting the export of audiences to disable bad actors and their use cases, it doesn’t apply to the data brokers themselves. So, the whole system of a data brokerage is available to anyone who owns a data brokering business or consumes raw data from DMPs and other data providers: a use case I am sure is used by threat actors. Good comment!