OK, first go to https://applymagicsauce.com/.
Can you see that somebody who have access to your likes on FB is able to say so much about you?
It isn't small thing.
Thanks to this in UK Brexit won, in US Trump won.
Knowing what kind of personality you have, which demographics you are, somebody may decide that it will be better if you will not vote, so they will show you some bad things about candidate you wanted to vote for. Or they may decide that if they hit in your "sweet spot" you will vote for theirs candidate.
This is manipulation on personal level.
They may touch your most hidden fears and use them against you.
So, delete your Facebook account.
Or at least, stop using Like and other reactions. At least your personality model may be little bit out of sync. And they will not hit you so much....
OOo2GD help site
Google Buzz - let's mark some comments as not spam ;-) or how to unhide "hidden" comments ;-)
How to create valid file name?
Borders, immigrants and so on