Another sibling comment was added 2 minutes ago, where Reddit themselves state that the blackout is the cause:

> According to Reddit, the blackout is responsible for the problems. “A significant number of subreddits shifting to private caused some expected stability issues, and we’ve been working on resolving the anticipated issue,” spokesperson Tim Rathschmidt tells The Verge.

Maybe you should think a bit harder about the difference between "this thing that is actively happening could be the cause" and "aliens could be the cause"?

If they anticipated it, why did it become an issue?

I do not work for Reddit. Maybe they have some press contact info on their page you could try? Or Twitter or something?

That was more of a rhetorical question.

Which one of these possibilities is more likely?

a) it was the incredibly rare event affecting most of the popular content on the page, which the host themselves state it was

b) it was something completely unrelated

I know which one I'd put money on!