Any publisher already had the option of blocking their content from being linked on Facebook and Google, they chose not to do so because the traffic they get from F/G was valuable.
I'd say the only time I ever read SMH is when there's a link in my FB. When mates or groups I'm a part of drop a link in. To be honest, I don't remember the last time I read general news that wasn't in my feed.
Apart from a few other aggregators (hackers news included)