Personally I think it should be illegal for governments to use software that can't be given away for free (as source if requested). Anything produced by the government is public property and should be published in publicly accessable form ergo, propriatary files are out. A member of the public, should they have the required skill, should be able to craft something that can read the document without legal consequence, just as anyone with the skill to read can currently read documents printed by the government without having to worry about whether decoding the symbols into meaning contravenes someones patent.
