Web 2.0 may come with a dark side, Tim O'Reilly, founder of O'Reilly Media, said in his keynote at the Web 2.0 Expo this week. In his mind, it started when Google and others learned to rank pages and amass data.

"What we used to think of as a computer is really a device connected to a global computer," he said, where more and more data is kept in what is increasingly referred to as the cloud.

"It leads us again to large centralized players," he said - possibly back to the type of world that Microsoft used to dominate.

"It's a big part of Web 2.0 that we have to be aware of and worry about," he said. "Every Web 2.0 race is a race to grow that database. Bigger is better. Google, Amazon, eBay all want to get all these things in one place.

"The paradox in Web 2.0 is that applications built off open, decentralized networks lead to concentrations of power. We have to build interoperability into the next layer," O'Reilly said. "The programmable Web really matters."

Link to the article: Web 2.0 Expo: Beware centralized power