...for example, the first Show HN on the front page right now. Doesn't work at all when cookies are blocked—it just renders some stars and some chrome.

But okay, I'll run it in another browser. Wow, it's a really cool WebGL visualization of global temperatures. And what is it using localStorage for? It sets one key called `runOnce` to `true`. I think that could be considered optional. Easy to fix, if they knew about it.