At that point, why just stop at friends? Why not go to any transitive relationship with the argument "well, you trusted that person, so it's just like them sharing the data you already gave to them". Of course, the absurdity of that is that one person can share the whole world. I do not think this is a slippery slope argument at all, given that FB already went halfway down the slope before there was outrage.
I despise Facebook, but I really don't understand this whole Cambridge Analytica thing. There doesn't appear to be an endgame for those criticizing Facebook over the ordeal. Of all the despicable things Facebook has done, why is this the one that everyone clings to?
In the end, it's still Facebook who handed over my data. That my friend decided that was OK doesn't change much.
Unless there's a major security vulnerability, you can only delegate access to data you have access yourself. So your friend did the equivalent of giving Cambridge Analytica your data - the technical implementation of it (as to whether CA got the data off your friend's phone or from Facebook directly) doesn't really change the outcome.
https://www.zdnet.com/article/facebook-sues-two-chrome-exten...
That is false:
https://en.wikipedia.org/wiki/Facebook%E2%80%93Cambridge_Ana...
I wrote this comment for people in this conversation to see. Yet you allowed Google Chrome access to the comment. You let your adblocker see it. You let lots of software companies scrape it. You shared the data with a wider audience than I intended.
Sure, the argument doesn't hold much water on the public internet. But now consider HN was an invite-only forum, in fact an invite-only forum just like my facebook page...
I think a lot of people are forgetting that you were also able to get tons of data on a user's friends, just from that user accepting. No consent on the friends part. If you and I were FB friends and I accepted one of those requests, CA now also knows your profile info and likes.