I know, more than 75 percent of the people on this earth who know how to use a computer decently, can obtain music illegally. Now, my question to go further about that is:

Do you believe people post songs of albums that were just released on YouTube to promote the ban, gain views, or to see what the record label company will do by forcing them by removing the media?

For me, it would be to promote the band. Although, some bands are cool with it or don't go to the extremes some bands would go pass go and screw you up if possible.

So in conclusion, is it a good deed to upload a song that isn't technically out yet?

Considering most bands with any sense already do this with the songs they want out there themselves, I'd have to say posting the song before the band is a bad idea. Regardless of your moral standings, it's just smacking the hive.