Ideas can't be copyrighted.

I have an idea for an article on when and how to create multiple file groups

I have an idea for an article on backups types and restores.

I have an idea for an article on statistics maintenance.

If you go and write articles on those subjects and publish them, I have absolutely no grounds to complain that you stole my idea. Now, if I write those articles, publish them somewhere and then you copy the text of those articles and republish, I have grounds to complain under the copyright laws of the relevant countries.

When you write for a site, there'll be an agreement between you and the site as to who owns the copyright, republication rights, etc, etc. Read any such agreement carefully. If, afterwards either party breaches the agreement, you have ground for action under contract law. Feel free to consult a lawyer for more details.