I'm really two-sided on this issue.
On one hand, I agree with Darkhououmon and others in this topic to an extent. The concept of blocking someone's (sometimes hard) work because it contains a section of someone else's work is a slippery slope. Someone did the work to produce something for the public BASED ON an existing work because the existing work is interesting to others and therefore a review/cover/commentary/music video/etc. may be interesting to fans of the original content.
The point where I really struggle with this issue is, what gives me the right to use someone else's hard work to get myself ahead (even if no money is being earned, just reputation, pride, fun, etc.)?
If I produced something on a large scale and sold it, I'm not too sure I'd want 'Average Joe' using part (or the entirety) of my work without my consent nor without any idea of how many people are doing so.
Let's try one scenario:
For example, let's say I make a movie. You own a movie review website. You review my movie. Your advertising/sponsors pay you based on your traffic. You are making money because my movie exists, but you never even have to contact me. This is apparently okay.
Let's try another scenario.
I own Apple and I design and sell the new iPad 3 (sake of example). You see it and decide, hey, you want to make a device that can run iPad apps..but it's not an iPad. You sell your device which runs its own software but is also designed to be compatible with iPad apps, to increase your "traffic" (consumer base). This would be very illegal without my permission.
What exactly is the difference?
If you want to make a successful youtube channel (or other venture), I encourage you to use more original content rather than relying on the success of others.
With that being said, I do understand that people enjoy making fanmade music videos, etc. etc. At which point in history was it ever acceptable to do that though? Movies have had warnings at their beginnings for decades now, explicitly stating that public performance of the 'licensed' (not owned!) video is illegal.
To me, it almost sounds like people are wanting to change the rules, now that they have computers powerful enough and media available enough to play with. It was never okay to publicly perform someone's copyrighted work directly, without consent.
As a final closing comment, what is youtube's name and slogan?
YOUTube: Broadcast Yourself.
Youtube was originally designed for users to create original content and share it with the world, not exploit to step the boundaries of copyright ownership.
