Problems with PDF Password Protection.md

Research into why Password Protection for PDFs is ineffective

• Adobe Acrobat Encryption & PDF Password Security
• Adobe PDF Security Issues, Acrobat Vulnerabilities, PDF Cracks
• How to protect PDF files without passwords
• Password Protection of PDF Files: Are PDF passwords secure?
• Unlock PDFs: Cracking Adobe Password-Protected PDF Files
• Remove PDF Password Protection & PDF Security Restrictions