Well, yeah. What people do on Facebook, they could do just as well on Google Docs, or WordPress, or YouTube, or WebMD, or anything else that combines any form of publishing with any form of messaging.
The way people go on about Facebook is like saying that we couldn’t have written language without Trapper KeepersTM, and wringing their hands because it turns out Trapper Keepers contain caesium-137, but what alternative is there?
