Watermark On Pdf can add watermarks to all or some pages of a PDF file. If you then secure the document with a password to prevent changes, it can't be removed
Watermarks are useful for protecting the copyright of a document, and may include, for example, copyright text, a copyright symbol, and a notice, such as “this document was created under the Copyright Act 1995”. It's possible to include watermarks that are useful for identification, but it's not very useful if the watermark is used to make an impression on the page as it is scanned. The Copyright Clearance Center has a great explanation of watermarks. How Do I Secure My Images? The Digital Millennium Copyright Act (DMCA) of 1998 gives you a few rights, including the right to make copies, to give permission to publish, distribute and display the work, and to perform the work (i.e., perform it publicly or make digital copies). These rights only apply if you are the owner of the original work (that is, the photographer, writer, or document photographer.) If the image is in the public.