If you want a quick and easy way to block any website on your Mac using Little Snitch simply…
File > New Rule:
And select Deny, Outgoing Connections, Domains and then type the domain, eg:
Click on create and you’re good to go 
If you want a quick and easy way to block any website on your Mac using Little Snitch simply…
File > New Rule:
And select Deny, Outgoing Connections, Domains and then type the domain, eg:
Click on create and you’re good to go