on march-21 addressing the cambridge analytica situation, “We have a responsibility to protect your data, and if we can’t then we don’t deserve to serve you. I’ve been working to understand exactly what happened and how to make sure this doesn’t happen again. The good news is that the most important actions to prevent this from happening again today we have already taken years ago. But we also made mistakes, there’s more to do, and we need to step up and do it,” mark posted. 

here’s a background of events;

• as early as 2007 facebook envisioned that apps should be “social” enabling people to log into apps and share who their friends were and some of their information (birthdays, where they live, photos).  
• in 2013, a cambridge university researcher named aleksandr kogan created a personality quiz app and was installed by about 300k users, this enabled kogan access to the those who installed the app and their friends’ data. 
• in 2014 facebook required developers  to get approval first before they request information from people. 
• in 2015, facebook learned from the guardian that kogan had shared the data gathered from his app with cambridge analytica, and they were demanded to delete all their acquired data
• about same year, the guardian also reported that cambridge analytica was helping US presidential candidate, ted cruz, to use this as psychological data for its campaign against its political rivals
• in 2016, trump’s team was said to have invested heavily on facebook ads and involved help from cambridge analytica
• on march 2018, facebook CEO acknowledged that cambridge analytica may not have deleted all the data