My previous employer just sent me a "certificate of earnings" as a password protected PDF with printing disabled. (I understand the password protected bit, but it's unclear to me how something is a useful certificate of earnings if you can't print it....)

Fortunately it's relatively trivial to remove the PDF password and hence the use restrictions, providing you know the password (and there are no non-PostScript features in the PDF you need to keep):

• pdftops -upw PASSWORD FILE.pdf
• ps2pdf FILE.ps

(It'd probably be best to do this with a copy of the original PDF, just in case it gets changed in ways you don't want; for instance some font information could get lost.)

On a Debian/Ubuntu system, pdftops is in xpdf-utils and ps2pdf is in ghostscript.

(If you don't know the password it's also fairly simple to brute force crack PDF passwords as the protection mechanism is fairly week, and the password text search space is pretty trivial too for most users)