http://www.youtube.com/show/halo4campaign/videos?view=0 appears to have missions 1 and 3 (I didn't look because I don't want to spoil it). I found them by simply searching Halo 4 campaign mission X

Those were officially released campaign gameplays. The OP asks for leaked campaign gameplay.

My bad, I was under the impression there would be more footage, simply because of how many other spoilers there are. I guess I stand corrected.

It's all good. I'm just in super fanboy mode and trying to get my hands on every little shred.

If I had the means to record it, I'd revive my old flashed box for you. They certainly are teasing people hard with it.

Agreed. And they play the damned "Copyright Violation" card. Not on the game itself, but on the videos people post of the gameplay. I feel it's kind of ridiculous. They're trying to generate buzz and keep it under wraps at the same time. Sure, it's legal for them to claim copyright on it, but still.

As far as I understand, their usage policies are only if you wish to monetize your videos. Excluding MLG, no one is allowed to make money on H4 videos.

So basically, it's illegal to publish it on any YouTube partners' channel. Anyways, back on topic, MSFT is still actively removing every unreleased campaign video.

Not just partners, as anyone can monetize the video. The justification behind the active removing of video is the monetization. I'm gonna go back to searching.