Wikipedia isn't a reliable source considering whoever they like writes it, I could go on it right now and put you have to be the King of Siberia to get copyright.
I hate when people say Wikipedia isn't reliable. That's honestly not true. Most people will only edit an article if they know something is true.
That aside, it is gotten automatically by the person who first makes the work. However, you can't sue for it unless you register the copyright. So in a way, everyone is right XD
At least, I think that's it. I'm probably still wrong XD