Great question. I don't know.
I think most would agree though, that the absence of a good solution does not justify a poor solution.
I guess that anyone in the country who seeks out and obtains the illegal content is committing a crime, so the government could go after them through traditional means. (Although seriously, are we really going to punish regular people for accessing a social media site?)
Admittedly, banning an entire website at the ISP is far more effective. However, I'd argue it's effective in the same way that a cannonball is an effective flyswatter.
You can also ask it to repeat the letter A one million times. For reasons I don't understand, it will say "A A A..." for a while before hitting some sort of repetition limit and then it starts speaking gibberish.