Reddit? No hateful comments there then ...

Guess at least you can have moderators.

Sounds like Reddit need to add a video distribution system, it would be quite a thing to pick top vloggers and add them in to the current mix.

I wonder where Vi Hart stands WRT her content. Can she remove it from YouTube. Could she remove it via a copyright infringement claim?

Sub-reddits are like irc channels or usenet newsgroups, they can have owners and be moderated to whatever degree those owners desire. Some sub-reddits are very tightly moderated.

Or Reddit needs to focus on providing a good API and Disqus-like embedding so they can provide Reddit-as-a-service for other websites. Right now sites can throw a skin on a reddit community and wrap it in a domain-name, but it's not really set up for embedding.