Every few months Facebook updates its privacy policy, which often times triggers a slew of users to post updates to declare their unequivocal ownership of all content they post on the social media site.
Unfortunately, the status update is meaningless and does not supersede the terms and conditions Facebook set forth when users signed up for their account. Also, continued use of Facebook's service means that they are agreeing to policy updates as stated in the latest announcement.
Basically, users can't back out of a contract they have already signed. And besides, according to Facebook's latest update, they actually still do own all of the content they upload onto its servers for free - they can just use it for any Facebook-related things they want.
The current surge in copyright declaration status updates seems to have been prompted by a notice from Facebook that appeared in user's notification areas saying that it is updating its terms and policies on Jan, 1, and continued use of the service means that users are aware of and agreeing to the changes.
