Yep. That's why, for feedback purposes, I created a social group, from where I send out chapters for critique to certain individuals through PMs, rather than open posting. It has it's drawbacks, and you don't get many takers, but it works for what I'm after.
Any other questions, be they technical or legal, just give me a holler and I'll do my best to oblige.
And yes, I do take my writing very seriously. I'm not published, not yet, but that is my goal. I'm writing a modern fantasy novel right now, and it's a little over half done, so we'll see where that takes me.
Copyrights are a tricky thing. As far as I know, Fair use applies to all things posted upon the internet, at least in regards to forums. The copyright is still yours, as it is presumably your original work, but by posting it upon forums you are indeed allowing your copyrighted material to be viewed by the general public. They can't copy it and claim it to be their own, by any means, but you still are agreeing to let them see it and/or use it by posting.
That said, I don't believe you can "get" a copyright, as it is inherently yours to begin with. If you are hesitant about posting something, then don't. Sometimes publishers will be wary of a work that is already out in the public, as then why would anyone buy it if they can get it for free? Use discretion and your best judgment.
I'm no law professor, so I could be wrong, but that's at least the way I perceive it.
Where can you get copyrights for things you post on the internet?
As a fellow writer (would be writer actually) I would like to discuss some things with you. You gave the impression that it is your career, or at least something you take seriously, and I have some questions.