At the very least, all these Web 2.0 tools make it easy, fun and tempting for everyone and anyone to start dumping mass amounts of their collections into the public arena where at least it's more accessible. Even the tools that have been online and technically free and open for years already (like library catalogs or government databases) are being made more "crawl-able" and/or pushed into view with RSS feeds and the like.
He who has nothing and wants something is less frustrated than he who has something and wants more.
Eric Hoffer (1902-1983), True Believer or Theory of Leisure Class
Check out the photos at flickr's "The Commons".