How to password protect a PDF in Adobe Acrobat Reader and shield your sensitive data

To password protect a PDF in Adobe Acrobat Reader, you'll need the paid Pro version, which starts at $14.99 a month.
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Abobe Acrobat Pro Too Expensive? Here's How I Password Protect PDFs (For Free)

At some point you’ll likely need to send someone a file that contains sensitive information, such as tax information, financial details, your Social Security number, or other confidential data.