Here are some free PDF apps that offer better privacy features:
- Evince. This is a simple and elegant PDF reader. It’s fully open source. It was originally available only for Linux but now supports Windows, too. It doesn’t have much in the way of editing features but if you just want to open PDF documents quickly and securely, Evince is an excellent solution.
- SumatraPDF. Another great open source PDF reader if you only need to read PDF files. It only works on Windows.
- Inkscape. If you need to edit PDFs in a serious way, this open-source app is your best option. Inkscape is mainly intended as a graphics-design platform, but it can work with PDF files. (GIMP provides a similar solution.) Unfortunately, it’s not as good for editing PDFs as Adobe Acrobat Professional, but it’s a lot more private.