Last Wednesday, Adobe Systems acknowledged a vulnerability in both Adobe Reader and Acrobat that could be exploited using malware to release sensitive system information. Under certain circumstances, it is possible to discover the existence of local files on an end-user system using XML scripts.
The problem affects versions 7.0-7.0.1, and is located within the Adobe Reader control. According to Adobe's Support Knowledgebase, the impact of the flaw is minimized because attackers would need to know complete filenames and paths in advance in order to exploit the vulnerability.
OK, so you want to stamp your document. Maybe you need to give reviewers some advice about the document's status or sensitivity. This tip from author Ted Padova demonstrates how to add stamps with the Stamp Tool along with related comments.