Chris Poole delivered the most powerful 10 minutes of Web philosophy of the afternoon at Web 2.0. The man formerly known as moot - founder of anonymous image sharing den 4chan and its new, better-lit cousin, Canvas, gave us a rousing and principled picture of what the big players get wrong about online identity.

"Google and Facebook would have you believe that you're a mirror," he said, "but in fact, we're more like diamonds." - multi-faceted. It was an appeal reminiscent of the one he gave at SXSW earlier this year, but it hit harder. Google Plus has since arrived, and Poole says it's even worse than Facebook for the future of online identity.

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Identity Is Prismatic

"The portrait of identity online is often painted in black and white," Poole said. "Who you are online is who you are offline." That rosy view of identity is complemented with a similarly oversimplified view of anonymity. People think of anonymity as dark and chaotic, Poole said.

But human identity doesn't work like that online or offline. We present ourselves differently in different contexts, and that's key to our creativity and self-expression. "It's not 'who you share with,' it's 'who you share as,'" Poole told us. "Identity is prismatic."

Choosing Our Own Identities

"We were on the right track at one point," Poole said. In the early days of the Web, its creators used their real names because they were the only people online. As the namespace got more crowded, people started using handles.

AOL Instant Messenger brought screen names to the mainstream. Poole said he agonized over his AOL handle, because he knew it would be a representation of him. That insight persists today at hacker conventions, where the real Web experts hang out. People there introduce themselves with their handles, because that's how they have chosen to identify.

"Twitter does the best job of this" of today's major social networks, Poole said. The platform itself uses handles and allows made-up answers in the real name field. Furthermore, "most of the apps allow multiple accounts. Facebook would never allow this, right?" He says Google Plus is the worst; you don't even get a vanity URL to distinguish yourself, and we all know how Google Plus handles pseudonyms: they delete the accounts.

Google & Facebook Are Eroding Our Options

Google and Facebook are "consolidating identity and making people seem more simple than they really are," Poole said. "Our options are being eroded."

Poole's bottom line is that there's a big market opportunity in this authentic, fluid kind of identity, which the big players are willfully abandoning. "You can incorporate identity without forcing your users to sacrifice something." Poole believes a Web network can validate an account using legitimate services without forcing the presentation of that user to be an over-simplification.

Creativity and self-expression are at stake, Poole says, and he's particularly concerned about young people. Facebook's new Timeline will lock people into their Facebook identities from birth.

Speaking at Facebook recently, Poole told its developers that they set the bar for identity, but he has since realized he was wrong: we, the users, do. "We're about to sacrifice something that's valuable, and it's special."

"I would ask us all to strive for this ideal when we design products, and as users on the Web, what we demand of services," Poole said. "Facebook and Google do identity wrong, Twitter does it better, and I want people to think about what the world would be like if we did it right."

Check out the Web 2.0 schedule and watch the events live here.