A-PDF Password Security (http://a-pdf.com/security/password.htm ) is a professional program that allows you to change the password security. You can set password to protect your PDF from copying, editing or printing. You can apply permission to a number of PDF files just in seconds. For more: http://a-pdf.com/faq/index.php?title=can-i-apply-permissions-to-pdf-so-as-to-prevent-any-copying-editing-or-printing-by-using-a-pdf-password-security .
