I can understand Hollywood getting pissed that movies are being illegally posted online but part of that is their own fault for multiple reasons. One of them is that most movies or TV shows have yet to made public via DVD/Blu-Ray or digital download. For example, there are tons of import shows from Japan where a lot of people want to see (I.E. the Kamen Rider and Sentai series) but its not happening due to companies sitting on them and not considering the idea that there is a market for this stuff outside of their own country. Same with Hollywood, especially older movies that haven't seen a new release since it was put out on VHS. There is a lot of profit to be made, maybe not big profit, but you have to think long term rather than focus on the quick buck.
In regards to the "Let's Play" copyright issue, YouTube/Google, the movie, and the games industry need to get their heads out of their asses and figure this shit out properly. Because if they continue with shutting down channels and hurting the people, THEY WILL FUCKING LOSE! What makes me sure about that? Talk to the music industry about their legal battle against Napster. When someone made a program where people can share songs and movies for free, the corporations tried taking them to court for cutting them out of their profit. But, ironically, they began losing money due to the countless lawsuits they had to file. Also, Steve Jobs came along with iTunes and not only revolutionized the industry but made the companies carrying out these lawsuits look even more retarded.
I admit, its a different situation than what YouTube/Google have on their hands but its boils down to one thing-companies trying to resist change. Companies need to learn how to adapt to the ever evolving presence of technology and they need to hammer out new copyright rules that will benefit all parties and not just themselves. To me, what these channels are doing is offer free advertisement for new and older games. I'm willing to bet that if someone watches a tutorial on a new fighting game or a "Let's play" on a classic game, they will want to purchase and play this game. They need to take advantage of this and not strike down people who could be working alongside you. If they continue to step on the backs of the people, then they better not act surprised when the people strike back.