Companies usually password protect their docs against unauthorized editing to keep someone from modifying the files and redistributing them. Canon, the camera company, goes so far as to place a layer with the huge word "COPY" running diagonally across the page. You want see that layer on your computer but when you load the PDF to an eInk reader or tablet device it shows up. Some companies are chicken manurish and block the printing of their docs too. You can download the unprintable version for free but you have to pay for the printable version, even though you just bought their product.