I've gotten reports from people that they think they're being blocked from commenting here! I'm truly sorry about that, and think it's either Typepad, a browser issue, or (more likely) a Typepad-talking-to-browser issue. (I've had it myself, and usually just copy my comment, click off my comments, click back, paste in the comments, and hit post, and it usually works--I'm on Firefox on a PC running XP).
For the record, I wouldn't block anyone unless it was someone who was a persistent spammer (and I mean actual spammer) or someone who was deliberately and repeatedly trolling and attacking. (And I'd talk to that person first, either offline if the person left a real email address, or in the comment section if not). Not someone who was discussing and just got heated. One of the things I love about this site is that people can and do get really passionate, but eventually we manage to work around to understanding, if not agreement.