Send to a Friend

Is it legal to record Minecraft gameplay, post to YouTube, and get money from YouTube ad revenue?
Is it legal to record Minecraft gameplay, post it to YouTube, and get money from YouTube ad revenue on that video? I see someone has already done it: http://www.youtube.com/watch?v=k20vcw3l0c4 but I want to make sure before I get deep into it.
Using Fluther
or