Charles Tan is a pseudonym that couldn't be more plain. But the reason I keep this up is because I dislike anonymity. But let me qualify anonymity. Fortunately, Gerry Alanguilan already talked about it in his blog. Banzai Cat (a pseudonym, trust me), for example, isn't anonymous even if I didn't met him in real life. If he went Stalker001 one day though and then Guest004002 the next day repeating the same comment, yes, that's anonymous.
So why the anti-anonymity? Bokardo says it best in 3 Necessary Conditions for Human Cooperation.