The real problem is how the information was utilized by the recommendation engine, which is known to be creepily effective at matching people (people who just met for the first time, for example). FB is investing heavily in AI here so this is the natural outcome - where the results are very effective but has some unintended side effects. The side effects are largely due to the fact this connectivity happens in the background, outside of a place where the user can control privacy settings on particular contacts.
So I'm not sure there is an easy solution here. Mining contacts and social information is Facebook's business. It's what you hand over to use the service and why many people stop using Facebook voluntarily - or carefully limit what information they allow access to. I never allow FB to access my phones contacts, for instance, and their mobile app still works fine.