I don't know how or why that was ever legal in the first place, and why Facebook and LinkedIn haven't been sued to death over it.
The contacts-matching system is how Facebook and LinkedIn'ss ultra-creepy "People you might know" list works, and I have no-doubt this will have led to things like journalists' confidential sources being discovered and harmful outing of closeted people, and worse.
Same situation with DNA. I may avoid getting an online genome test, but once a couple cousins send theirs in I'm basically a part of the network at that point
I don't know how or why that was ever legal in the first place, and why Facebook and LinkedIn haven't been sued to death over it.
The contacts-matching system is how Facebook and LinkedIn'ss ultra-creepy "People you might know" list works, and I have no-doubt this will have led to things like journalists' confidential sources being discovered and harmful outing of closeted people, and worse.