Sometimes you want to block all Facebook IPs for various reasons (1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 ). Sometimes you really really do want that (and you should do it), so compiling a list with all the IPs is easy (both IPv4 and IPv6):

$ whois -h whois.radb.net '!gAS32934' | \
	tr ' ' '\n' | \
	awk '!/[[:alpha:]]/' > facebook-ips-ipv4.txt
$ whois -h whois.radb.net '!6AS32934' | \
	tr ' ' '\n' | \
	grep '::' > facebook-ips-ipv6.txt

And a list of Facebook-owned IPs will be saved into the facebook-ips-{ipv4/ipv6}.txt files, ready to be used.