There are various document permissions you can set in Acrobat to control what users can do with your PDF files.
Below is a list of PDF restriction options available:
Printing: If printing is not allowed, the print button in Acrobat will be disabled.
Adobe also lets you select high-resolution and low-resolution printing. Low-resolution printing generates a low quality bitmapped image of the page which is suitable only for personal use. Bitmap printing also considerably slows down the printing process.
Changing the Document (editing): If this is disabled, any document modification is prevented. Content extraction and printing are allowed.
Document Assembly: If this is disabled, inserting, deleting or rotating pages, or creating bookmarks and thumbnails is prevented.
Content Copying: If this is disabled, selecting document contents and copying it to the clipboard is prevented. The accessibility interface also is disabled.
Page Extraction: If this is disabled, extraction pages from the document is prevented.
Commenting: If this is disabled, adding, modifying, or deleting comments is prevented.
Form Fields: If this is disabled, form field filling is prevented.
Signing: If this is disabled, signing documents is prevented.
Content Accessibility: Allows accessibility software (such as a screenreader) to use the document contents.
Removing PDF Restrictions
PDF permissions are ‘protected’ with the use of an owner password. However the owner password can be easily removed in seconds with freely available PDF password removal tools.
Also third party PDF readers do not have to honor these controls which effectively renders them useless.