Livre d'Or

If someone writes something that insults me then if it's so niggling that I have to do something about it, I'll make a locked post in my LJ and don't mention names.

I don't often find myself in that kind of situation; the world is a bitchy place and there isn't much of it that won't take delight in pissing off someone like me. But when something does get to me then I accept both that I need somewhere to vent about it and that the person doing the pissing in the first place isn't going to appreciate me doing so to all and sundry.

This is slightly different to the situation that you outlined, though, where an opinion is expressed that I disagree with. In such cases whether I reply - and I will usually do so as a reply to the original post or comment - depends on whether the issue is important enough that I think a contribution from me will help the discussion at all. If there seems to be a real point that is unlikely to be brought up by someone else, I will say something; if it's more about my feathers being ruffled by someone being obnoxious, I'll go and do some knitting or something.