Facebook said Wednesday that it believes most of its users who had a specific search function enabled have had their profile data scraped by third parties.
“We’ve seen some scraping,” CEO Mark Zuckerberg said on a call with reporters. “I would assume if you had that setting turned on that someone at some point has access to your public information in some way,” he said.

As we’ve seen over the last couple of months/years, Facebook has been playing it fast and loose in terms of our data and identity on their site…and how they’re manipulating your feed to keep you on there for longer periods of time.
It’s also important to recognize that Facebook is acting as they are designed to act. You are the product that is being sold. If you share content openly on Facebook (or other social spaces) you cannot be surprised if/when people can “scrape” that data.