Well, the conversation has apparently gone from asking why someone needs total anonymity when conducting completely legal activity online to protecting oneself from signals intelligence agencies. I have a vested interest in protecting my sensitive information online from identity thieves, scammers, people who would want to rob or injure me and people making arguments like the one I responded to who would likely use my information to embarrass me in an attempt to make a point about having "nothing to hide." When I have a credible reason to add the cops or the NSA to the list, I'll start taking measures to hide my perfectly legal activity from them as well.
The reason I don't fear them isn't because I believe they're infallible, free from abuse, etc. - the reason is that I'm significantly more likely to be assaulted by one of the hundreds of people that walk past me on the way to work than targeted by a rogue NSA agent trying to collect my online activity, and yet I can still walk down the street without being scared of everyone around me.
In the mean time, I know that if the NSA or FBI wants to target me they need a court order, and if I'm going to be arrested and tried in court the cops need evidence of illegal activity to convict me. When I see credible evidence that this is not the case, I'll take steps to protect myself from them. Despite more than a year of Snowden revelations, however, Greenwald and friends have yet to show evidence of a single American being thrown in jail because of the vast, Orwellian surveillance state that has supposedly developed around us.
If it was happening, that would have been the first thing they reported a year ago. The fact that they have yet to come up with anything tells me that in that giant trove of the NSA's deepest secrets, there is nothing to indicate any harassing or incarceration of regular citizens.