I do not own any portion of any photos pinned or described, it belongs to its rightful owners. No copyright infringement intended.
Googling site:pinterest.com "no copyright infringement intended" yields 530,000 results. This means that more than half a million "pinners" believe that this disclaimer protects them from claims of copyright infringement, as the infringement was not intended.
Not to compare copyright infringement with violent crimes, but this is like going into a bank with a gun and a nylon stocking over one's head, demanding money from the cashier, and shouting: "I don't intend to rob this bank! I don't mean to steal this money!"
Looking at the context of this bizarre disclaimer, one can see that it underlies a complete lack of understanding of what copyright infringement is. Some write: "posted for inspiration only; no copyright infringement intended" as if a claiming a non-commercial purpose makes infringement more tolerable.
Some will even boldly acknowledge that they are infringing, followed by the disclaimer "I do not own any portion of any photos pinned or described, it belongs to its rightful owners. No copyright infringement intended." They KNOW that they are infringing copyrights, and they're worried about it enough to draw attention to it - but they want us to believe it was unintentional, and that makes it OK.