Longtime readers of The SF K Files know that I have seriously considered requiring registration on the site. At one point, I introduced registration but later turned it off after so many readers convinced me that this was the one place where they could freely share their feelings. I also introduced a poll where readers voted on whether to require registration. They voted it down.
I'm now introducing registration again because there's a serious spam problem within the comments, and it's becoming cumbersome to read. It's openID registration so you don't need to identify yourself by name and you're free to choose any username. But this will allow me to block spam.