In the US, any documents produced by the federal government are in the public domain and not covered by copyright. However, that's not necessarily true in other countries. Australia, for one, has the concept of Crown copyright, where the government retains copyright on its documents. Sometimes that creates ridiculous scenarios, such as last week, when Google was trying to create a map overlay of useful information about the extent of the massive Australian bushfires that killed hundreds. Instead of being able to map all of the fires, the Victorian Department of Sustainability and Environment denied Google's request to get data needed to plot the fire's location on public lands, citing Crown copyright. Yes, it appears the government blocked this useful resource because of copyright issues.