How can I make some restictions in a PDF document using Acrobat 9 pro?

Question

Hello, I am a teacher from Spain. I am creating a PDF from a power point presentation, using Adobe Acrobat 9 pro. I will copy it in a cd and give it to my students. I would like to add these restrictions:
I would like to avoid that they can copy this document.
I only want to allow them to print it once.
Thank you

Answer 1

You can prevent copying of content (text and images) by setting permissions on the PDF file using Acrobat (apply password security, leaving the document open password empty).
It is not possible to limit the number of times a PDF file is printed, no matter what settings you use. Printing can be disabled completely, or restricted to low-resolution output, but that is all. Even if it were somehow possible to restrict how many times Reader or Acrobat was allowed to print, there is no way to stop someone changing the copy number in the operating system print dialog, as that is beyond the control of any installed program. A printable PDF file can also be printed to another PDF file (called refrying), which will remove any interactive restrictions on the original.
Note that permissions security is only respected by Adobe software. Third-party applications will often ignore the restrictions and allow all operations. The only way to truly protect the file is to apply a security method which is only found in Adobe products (such as LiveCycle policies), which will as a side-effect prevent anyone from opening the file in a third-party application that might not respect the restrictions.