You give facebook all your information willingly and for free - and then people are surprised when facebook sells the information? Facebook's business is not to protect your information.. its to sell your information to advertisers. You're paying to use their platform to connect with your "friends" by giving up your rights to whatever they can scrape off your phone.
This is not a surprise.
Mr. Zuckerberg will appear before the panel and promise data-security changes but at the end of the day facebook is still a business for advertisers wanting your shopping lists, contacts, interests, and personal profile to sell you stuff. The only thing that will change will be facebook's vetting process so only "friendly" corporations like walmart and BP have access to everything Cambridge Analytica had.