I was thinking about this a lot, and in a way, I can kind of understand the angle of the games companies from the point of view that people doing let's play type vids are 'giving away' or 'letting people experience' the content they spent lots of money to produce, program, etc for 'free'. I mean this isnt like back in the days during the christmas break when we would invite a couple of friends and marathon thru Dragon Warrior on the nes; far more people are getting free rides here..
This is just an exemple, I remember a rant on twitter or maybe in an interview from Ed Boon where he was talking about how sad he was that all the fatalities and secrets of his latest MK game were available on youtube the day before the official street date.
It kinda sucks!