[scientator]

The title is misleading in the sense that the article concerns the cosmological principle, which is (as the name suggests) a principle, not a law. That is, it's a guiding assumption, or paradigm. It's been guiding cosmology since the time of Newton. But I'd argue that cosmologists didn't adopt the cosmological principle based upon observations of the cosmos, but rather because if they didn't adopt it, then making any hypothesis about the cosmos as a whole would be next to impossible. The fact that observations may now be suggesting that the cosmological principle doesn't apply to the large-scale structure of the universe suggests that there may be hard limits to what we can know about the cosmos as a whole.