Re: How about some background?
That sort of distinction certainly used to exist in the UK. If you were a photographer was held by who owned the film. Not a perfect rule, but a simple enough distinction between a newspaper employee and a member of the public. In the age of digital cameras, the difference is less clear.
What matters most of the time is the licensing of the copyright. Why should a social media site need to own the copyright? All they need is a license to use the material?
Some of the stuff, on both sides of the arguments, seems to come from lawyers who know very little of what the technology does.
And at least some of these claims struggle to be consistent with statute law.
The details vary, but the same things keep on happening about different material. The US requirement to register copyright to get any protection ended in the 1970, but you still see cases of companies claiming your work isn't protected, (US registration adds to the protection: for one thing, it proves a date for the work)
And the "(c)" doesn't work. Use "©".