It is not my intention to anger anyone, I'm not an idiot, I know what you can find on YouTube, is it all legal? No, not by a long way, could the BBC and other broadcasters get YouTube to remove their stuff, yes, but it will cost them because they have to have employ people to scourer the site looking for their material.
Once you've found it you need to show proof that you own the copyright, which involves writing a legal letter/fax to YouTube, luckily now there is an online form you can use. Last time I used it YouTube suggested I might have made a fraudulent declaration, but they were very good once they were given the relevant details, and the films were removed. The BBC is now increasingly becoming just a broadcaster, they don't own the copyright for all the content they broadcast, so it's left to the individual production companies to chase down uploaded content. They are quite likely small and struggling with ever decreasing budgets, and so will only have limited resources to combating YouTube, Google Video, Vimo etc. Then there are the pirate copies being sold on ebay, that's fun, that's more legal letters, then the same person pops up under a different username, and you start the whole thing over again. Then there are the major download sites, and if the major software companies, major music labels and movie studios are struggling to get to grips with it then what chance does the independent film maker have?
However you seem to indicate that you think it morally okay.
I guess it depends whether it affect you and the people you work with and chose spend some of your free time with.
Chris