Yes, Facebook is up to even more dirty tricks. You expected something else?
Facebook is letting advertisers reach users with contact information collected in surprising ways.
Quoting an article by Kashmir Hill in the Gizmodo web site:
“Facebook is not content to use the contact information you willingly put into your Facebook profile for advertising. It is also using contact information you handed over for security purposes and contact information you didn’t hand over at all, but that was collected from other people’s contact books, a hidden layer of details Facebook has about you that I’ve come to call ‘shadow contact information.'”
The full article may be found at: https://tinyurl.com/y7hedkv5.