@Ant:
I have the same version of SumtraPDF (3.1.2), so I opened a file converted using the PDF Anti Copy Pro software offered here, and clearly the Printer icon in SumtraPDF is grayed out (cannot print). In the File menu, the small menu that has the Print option, shows “Print … (denied)”, so I am pretty sure you did not convert the file correctly. In addition to selecting which pages (or all page) to be “protected” you also have to check one or both of the boxes under the list of pages that state, “Prevent Printing” and also “Prevent Copy Function” before clicking the Start now button.
If you can print a file, you are probably opening the source file, not the output file created using PDF Anti Copy Pro.
There is no reason that the PDF Anti Copy Pro software could produce a PDF file that would work for some PDF readers and not others. If SumtraPDF could print and copy the content, then all PDF readers would be able to do the same. SumtraPDF has no control over the file it reads; once protected, it is protected from SumtraPDF or any other PDF reader from printing or copying. The source code for SumtraPDF is available online. Someone would have taken that source code and created a reader that could bypass “protected” PDF files, except it is not possible.
There are several PDF utilities that are made to convert, encrypt, decrypt, split, rotate, and several other items, but none of those are going to allow the protected content to be printed. For example, if you extract a page from a file that PDF Anti Copy Pro has “protected” then you will get a blank page, not something you can print.
Since the protected PDF is essentially an image for each page, if you have PDF OCR software, you can run it on a “protected” file to see if it can produce output. You could use the OCR software on a screen capture of the PDF, but at that point you are no longer using the protected file, but instead working with the screen capture data itself.
The only way that a protected PDF file could be printed is if the PDF Anti Copy Pro software failed. Something in the PDF file would have to trigger PDF Anti Copy Pro to NOT protect the file, but still produce an exact copy of the input. If you can produce a file that PDF Anti Copy Pro does not protect, post it somewhere online so that the issue can be duplicated. I am sure the developer would love to see it, and so would I. That is the only that would make me doubt this software cannot do what it claims in all cases.