This is a fine requirement for many contexts. The more important the decisions being made based on those words, the more important that identity come into play. I won't take life critical advice from the whispers in forums, for example.

However, requiring strong identity is the hallmark of repressive regimes the world over. Look at China, where saying the wrong things can lead to police investigation or even prison. For those of us who live in free societies, we tend to dismiss “how bad it could be” and see anonymity as a luxury. In some countries minority viewpoints can only be expressed via anonymity.

4chan does not have noble intention and ignoble people tend to flock to such out of control situations. Some good may escape, but probably not enough to “justify” the time and energy spent on it. Wikileaks exemplifies the other extreme of anonymity: the ability to blow whistles and call out governments or corporations that wish to hide from the truth of their actions. Some good may come of it; in fact, I believe Wikileaks balance sheet to be positive.

Do we want an Internet Drivers License? ( http://curiouscapitalist.blogs.time.com/2010/01… )

China does; that is enough for me to rail against the idea.
Interestingly though, Wikilieaks itself is non anonymous. The site does not permit every conspiracy theory or crackpot statement, but requires documents to carry authority, even if they are provided by anonymous sources.