Security and Accessible PDF File
If you are concerned about your accessible PDF files and security, you're in for a real treat! Acrobat 5 has just the feature you're looking for.
Set the Acrobat Standard Security as you normally would, and follow these steps from the Standard Security window:
Select 128-bit RC4 (Acrobat 5) from the Encryption Level pull-down menu in the Permissions pane. The security options change based on the new selection.
Select Enable Content Access for Visually Impaired.
Deselect Allow Content Copying and Extraction (see Figure 6).
Change other settings in the window as you normally do.
Figure 6 You can disallow content copying and extraction while allowing content access for visually impaired.