Despite the enthusiasm and the persistence of its hundreds of volunteers, the task of Project Gutenberg isn't made any easier by the increasing restrictions to the public domain. As stated in the FAQ, "the public domain is the set of cultural works that are free of copyright, and belong to everyone equally." In former times, 50% of works belonged to the public domain, and could be freely used by everybody. Nowadays, 99% of works are governed by copyright, and some people would like this percentage to reach 100%. In the Copyright HowTo section, Project Gutenberg presents its own rules for confirming the public domain status of eBooks according to US copyright laws. Here is a summary. Works published before 1923 entered the public domain no later than 75 years from the copyright date. (All these works are now in the public domain.) Works published between 1923 and 1977 retain copyright for 95 years. (No such works will enter the public domain until 2019.) Works created from 1978 on enter the public domain 70 years after the death of the author if the author is a natural person. (Nothing will enter the public domain until 2049.) Works created from 1978 on enter the public domain 95 years after publication (or 120 years after creation) if the author is a corporate one. (Nothing will enter the public domain until 2074.) Other rules apply too. Much more restrictive than the previous one, the current legislation became effective after the promulgation of amendments to the 1976 Copyright Act, dated October 27th, 1998. As explained by Michael Hart in July 1999: "Nothing will expire for another 20 years. We used to have to wait 75 years. Now it is 95 years. And it was 28 years (+ a possible 28 year extension, only on request) before that, and 14 years (+ a possible 14 year extension) before that. So, as you can see, this is a serious degrading of the public domain, as a matter of continuing policy." The dates mentioned by Michael are: a) 1790, date of the stranglehold of the Stationers' Guild (the publishers of the time) on the Gutenberg printing press (hence the 14-year copyright); b) 1909, date of the copyright reinforcement to counter the re-publishing of large collections of the public domain by reprint houses using steam and electric presses (hence the 28-year copyright); c) 1976, date of a new tightening of the copyright following the introduction of the Xerox photocopying machine (hence the 50-year copyright after the author's life); d) 1998, date of a further tightening of the copyright following the development of the internet (hence the 70-year copyright after the author's life). These are only the main lines. The Copyright Act has been amended 11 times in the last 40 years.