OK, thank you
You're welcome however Facebook is a dragon with multiple heads and I block it 'effectively' with three lines for my local DNS sever (DNSMasq):
# No access to Facebook
server=/facebook.com/fbcdn.net/facbook.com/fb.com/fbsbx.com/facebook.com.edgesuite.net/instagram.com/
server=/facebook.net/instagramstatic-a.akamaihd.net/instagramstatic-a.akamaihd.net.edgesuite.net/
server=/cdninstagram.com/tfbnw.net/whatsapp.com/fb.me/
This works if you can control the machines connection not to have their own host files in which workarounds are defined to bypass the DNS server on these specific Facebook lines.
Blocking that would mean that you block each IP that Facebook uses and that are a LOT.
Facebook has their own AS Number and I am still looking for a script (internal/external) to make an address-list from that AS Number (AS32934). Just like we are now able to state a domain name and that in the internal DNS generating the IP numbers. This list can then be called in the filtering rules by the AS Number as name.