Board Thread:Support Requests - Getting Technical/@comment-9505648-20130123210516/@comment-188432-20130125231359

See Help:YouTube extension for more on what Fandyllic is talking about. It could create confusion on your site, depending on how much your users add videos to the site. You'll end up with two different kinds of video — those that are actually a part of your wiki, and therefore categorisable and searchable — and those that aren't.

It kinda depends on what you want.