[hombre_fatal]

You can do this on Reddit. No matter how successful and busy a subreddit may be without the presence of moderators, you can request ownership of a subreddit if the moderators have not been active in some time.

I found this out when someone did it to me. I had an account that I only used for moderation duties. I didn’t need to post on it. My community was doing just fine.

Well, Reddit transferred it to someone else and they turned it into an SEO spam generator.

[Laforet]

The reverse can also happen with people hoarding subreddits and refuse to hand them over to more eager people. Even when it is clear their interest have moved on, reddit admins will refuse usurpation requests because "the moderator is active".

[ComradePhil]

The downside to that is that you have to be on reddit.