>>>The song Happy Birthday to you" only came out of copyright in the last month
Not acually true. The court's decision was that the alleged copyright holders, who had been charging for the song's use, had never purhased the copyright to the actual song itself but only to the arrangement of it.
Lynn:
Youtube was originally set up purely as a site for people to put their home videos on. However it quickly got used by people posting videos of TV and movie content, together with sound recordings. Unsurprisingly, the copyright holders started demanding copyright fees from Youtube, which would (if agreeements had not been reached) would now be costing Google (which owns Youtube) many millions of dollars every day.
Youtube/Google eventually reached deals with many broadcasters (such as the BBC), movie companies, recording artists and record companies, permitting the use of certain content in return for the paymnt of fees from Youtube. (So, for example, the BBC makes quite a lot of money from clips of BBC programs being available on Youtube).
However not all copyright holders have entered into such agreements with Youtube. In particular, several leading recording artists have sworn that they'll never allow their music to be heard on Youtube. So Google have NO CHOICE but to remove any such content, as they'd otherwise be stung by multi-million dollar legal actions.
If you remember that it costs the BBC well over a hundred pounds in broadcast rights for every single track that's played on their national radio stations, you should be able to see how the bills could easily mount up for Google if they had to pay copyright fees. The 'punitive damages' that they would also have to pay for ignoring a recording artist's right to say whether they can host that artist's material on Youtube would be vastly greater.