How to stop haemorrhaging data on Facebook  https://theconversation.com/how-to-stop-haemorrhaging-data-on-facebook-94511 April 6, 2018

Go to Location Services in Settings , and turn off or select “Never” for Facebook.

Content: Change “Who can see your future posts” and “Who can see the people and pages you follow” to “Only Friends”.

Settings called “Do you want search engines outside of Facebook to link to your profile?” Select No. scroll down and limit the audience for past posts. 

Privacy Shortcuts – Limit who can see your personal information (date of birth, email address, phone number, place of birth if you provided it) to “Only Me”.  Privacy Checkup shows you which apps have access to your data at present. Delete any that you don’t recognise or that are unnecessary.

Turning off “Facebook integration” altogether. This is optional. If you choose to do this, it will revoke permission for all previous apps, plugins, and websites that have access to your data.

It is best not to use Facebook to login to third party services.

We need to talk about the data we give freely of ourselves online and why it’s useful https://theconversation.com/we-need-to-talk-about-the-data-we-give-freely-of-ourselves-online-and-why-its-useful-93734 
March 22, 2018 

What was considered ethical and appropriate five or ten years ago (such as the savvy use of social media by the Obama presidential campaign) may be regarded as unacceptable in the future. This is just the natural process of technology evolving over time in response to public scrutiny. Facebook operates in a highly competitive environment, as do the academics and entrepreneurs who want to make use of social media data. Some will always be more willing than others to take calculated risks in an attempt to leapfrog the competition. The world of big data analysis is like the Wild West. If we don’t collect and analyse these data, then our competitors will (and they will get the grants, or the big contracts).