UNESCO's International Day of the Book is also known as "World Book and Copyright Day". The accompanying blurbs on the UN and UNESCO websites emphsize the importance of reading in the first place, glossing over the copyright portion of their message. What is the copyright portion of the message? I'm not actually sure - but it involves linking to the World Intellectual Property Organization, so I presume its purpose is to err on the side of protectionism against copyright abuse. (I admire that the day was chosen because it was the death date of several authors whose works are all out of copyright.)
Yet the excess of copyrights and related protectionism in the world need not be an inadvertant way of making texts unavailable for use, by being out of print while still in copyright. This vexing problem is a widespread one - and why retain rights which are not being taken advantage of? Therein lies the benefits of posting work - even copyrighted work - in an accessible online forum.
Posting work online is not necessarily the same thing as "giving it away" - although it can be, if the author so chooses. Proof of this is the overwhelming numbers of poems, articles, chapters, excerpts, and entire books being "given away" in honor of papersky's brainchild, International Pixel-Stained Technopeasant Day, which is today as well. The related LJ community, ipstp, is full of posts of contributions to the day. Many of these contributions were first sold - some several times - before being released online. When the author retains copyright, they can do this with their work.
papersky was inspired to establish IPSTPD as an way of asserting the ways in which posting online can be an empowering act as part of an author's career, contrary to what one particular outgoing VP of the Science Fiction and Fantasy Writers of America believes. It seems appropriate, then, that she chose a day which commemorates the death of a major labor union leader (Chavez) in addition to a number of major authors of great imagination (Wordsworth, Shakespeare, Cervantes etc.)
Copyright and related licensing can be done a whole variety of ways. The Creative Commons is a nonprofit organization that makes available clearly-written licenses which can be used to publish work while making clear what protections it retains. Giving something away doesn't mean that copyright is lost. And what better way to celebrate the retention of copyright - and encouraging others to celebrate with you - than by giving something away for free?
* The title is a reference to both the visual image conjured in my head by "pixel-stained", and also an admission that I've been watching Any Dream Will Do, and thus have related songs stuck in my head.