Reviews for the blocks will take place every six months.

Officials maintain that this won't lead to arbitrary censorship. There's a "high threshold" and "parliamentary oversight" before blocking takes place, Inman said. Communications minister Paul Fletcher likewise said blocks didn't represent a "universal solution." This is specifically meant to combat material that's illegal in its own right -- in this case, a video of horrible violence effectively crafted to spur further terrorist attacks.

Even so, it's unlikely to completely satisfy critics. There are concerns this could lead to Australia blocking sites for content that exists in gray areas. And of course, there are questions over whether or not the government should block sites in the first place. Opponents have typically argued that any action should focus on the people uploading the video, not the hosts, and that those most vulnerable to extremist material won't be deterred by blocks like this.