I was chatting the other day with someone who had written an entry for Wikipedia, re-used the same material in a published article, and was worried (in my opinion rightly) about people accusing him of plagiarism and Wikipediism. This is a bit of a tangle, although responsibility for alterations to Wikipedia articles can be traced (don't think I don't know about that!), but it would take a bit of organising to construct the defence.
As for blog entries, well it is pretty clear to me that if other people want to take something written here and use it in some other forum it should be cited and referenced (whether on another blog, somewhere else on the internet, or in a published article or book). But it is not so clear to me when I am myself re-using and re-writing some thoughts that may have been expressed here in a preliminary manner. Sometimes then I would simply re-word the material without reference (although on occasion it will also be helpful to refer to the blog for discussion of the idea). I suppose if the final expression of my idea is substantially influenced by the discussion then a citation/reference is more important/essential. Perhaps it may be permissible (and realistic) to have a general note: 'some of the ideas developed here were first discussed on the Evangelical Textual Criticism blog and I am grateful for the discussion'.
What do you think?