Prelinger questions googles archive practices around government documents in his post titled Google Book Search treats government documents as copyrighted material
here is an example:
Here’s what appears to be Volume I of Violations of Free Speech and Rights of Labor,the famous LaFollette Committee hearings on industrial espionage, strikebreaking and other unsavory weapons used against labor in the 1930s. If you click on the link, you’ll just see snippets. This is a public domain document published in 1936 by the Government Printing Office.