Freemypdf.com is a free website that allows you to view restricted Pdf files.Use this site to remove passwords and restrictions (such as printing, copying text, etc.) from PDFs.
Note: This only works for PDF FILE that you open and read without any Third party plugins. PDF file that require a password to be viewed cannot be unlocked by this service.
This is because this is not cracking. Viewable PDFs with restrictions are not really protected, no more than a door with a broken lock, as opposed to password-protected PDFs.
Another great site which allows you to hack a Pdf password.To unlock a PDF file, enter it's location in the "PDF file to unlock" field, by either typing it in the field or clicking on the "browse" button, then navigating to it's location.
The unlocked version of the PDF will be displayed in a new browser window, opened in the default PDF application for your system (usually Adobe Acrobat Reader).