When is it okay to delete?

I have not had a need to do this in a long time, but today I deleted comments. I was appalled that someone would actually use a curse word on a comment, but they did. I don't think they know who or what I was talking about, I was offended by their language, and so I deleted the comment. Is that okay?
Normally I'd say no. Blogs are about open communication and being able to share ideas freely. If you don't want someone to disagree with you, then don't post it. I'm pretty good at walking the wire. If you're going to delete comments, well then you're not really being open in your discussions. No open mind, no need to blog. Sort of like the politician who blogged, but didn't allow responses because he didn't want to hear what the public truly thought. I want to say he was in Illinois, but I could be wrong. The Discovery Educator Network members and field managers were impressed that Discovery allowed the blogs and discussion boards to openly allow people to vent after the December 6 meltdown. They keep an open mind.
However, I do have a few readers, and those few readers actually read it in their school. Why do I want to give ammunition to the school administrators to block blogs when my own blog has a bad word on it - thanks to a comment? When I worked for Discovery, Steve had to delete a comment that was more on the lines of a bot spamming the site (Lady of the night and her offerings).
We want our students to blog- because face it, blogging has become their world. If they blog their homework response about whatever they read and relate it to their own world, they are more likely to retain the information and to pay attention in class. More likely to do the homework too. That whole point relates to a blog I read earlier. Anyway, back on topic. In the blogging world though, we don't always know who will be commenting and we don't know what people are going to say. There's a product out there now for school blogging that I really don't like. I don't like it because I found a whole bunch of student accounts and their blogs were not educational at all! I don't think the teacher was reading them because if they were they would have known who was planning to skip class, who was not doing work in the library but playing a game, and stuff. They actually turned it more into a Twitter application.
If you blog with your students, then this is what I suggest:

• Create settings that only registered users can comment. A few students might want to comment anonymously and have great reasons to, but by only allowing registered users to comment, you are protecting the outside world from leaving inappropriate comments.
• Check the blogs your students write, along with comments, and frequently. If you start something, finish it all the way through. If they are going to have access to it over the holidays, then you need to check it through the holidays.
  
• Make sure the site is safe. There are plenty of them out there. Some are free, some cost. Some parents wouldn't mind paying a few $$ to help with these costs, so keep your options open.
  
• Each student should have an agreement of ethical behavior for any and all online activities on file, signed by parents. I don't care if you're an elementary teacher using WebKinz in your class and you allow the student of the week access to the site and to take care of the virtual class pet. Sign an agreement and file it away.
  
• Model what you preach. If you want ethical behavior from your students, make sure you also display ethical behavior, even with your private online persona. I'm sure the kids can find that MySpace page, personal blog, or other item. Be smarter than they are.
  

You can learn more by reading works by such greats as David Warlick and Will Richardson.