Lifehacker has, in light of recent revelations, an awesome HOWTO explaining the ways to delete your phone contact data from both Facebook proper and the Facebook Messenger application:

Facebook’s terrible, horrible, no good, very bad week continues. Though the social network’s “contact import” feature has been around for a very, very long time, you’ve probably forgotten about it. And if you want keep Facebook from filling in the gaps by collecting data about your friends from you—or worse, records of your call data—it’s easy to shut your devices up.

To get a look at the contacts you’ve already uploaded to Facebook, you’ll want to visit Facebook’s Manage Invites and Imported Contacts page. You might be slightly shocked to see open invites from many, many years ago still active—just a little head-nod to the viral aspects of the social network back when it was still getting off the ground (and more of a collegiate gathering ground than anything else). Feel free to delete these; who needs an invite to Facebook nowadays anyway?

This will remove unwanted data from Facebook and will likely lead to less creepy “do you know Johnny” type friend suggestions. The entire article discusses a few different places on Facebook to visit to ensure specific personal data is deleted. If you have not yet done it, I strong suggest visiting this article and following the simple outlined steps.