You may have seen it come across your news feed or maybe you fell into the trap but posting a copyright notice on your Facebook does nothing and means nothing. It's not even new. From PCWorld.com:

"It’s a resurgence of an old hoax that many users fell for earlier this year when Facebook became a publicly-traded company. The previous hoax implied that the change from a private company to a public one somehow changed the rules of the privacy agreement and put your posts and photos at risk unless you posted a copy and paste of a disclaimer establishing your copyright ownership."

The text of the post looks like this:

"In response to the new Facebook guidelines I hereby declare that my copyright is attached to all of my personal details, illustrations, paintings, writing, publications, photos and videos, etc. (as a result of the Berner Convention). For commercial use of the above my written consent is needed at all times. (Anyone reading this can copy this text and paste it on their Facebook Wall. This will place them under protection of copyright laws.)"

Posting something on your timeline, news feed or page has no effect and creates no privacy protections, it doesn't change the Terms of Service users agree to when they sing up.

As with anything posted, forwarded or copy and pasted in a social media setting, check out Snopes.com. That is the best place to find out if somthing is real. Even if it was forwarded by your mom's friend's daughter that knows a guy who heard that it was true.