Blogger Damozel says she understands there are lines a responsible commentator shouldn’t cross, but asks where they are. James Joyner, of Outside the Beltway, is also uneasy about quoting extensively from someone else's work.
‘I’m actually surprised that this action is so late in coming. I’ve worried for years that the lengthy excerpts I use…could be ruled to exceed “fair use” but relied on the notion that I was adding enough commentary to create a transformative work.’
Damozel worries whether her commentary is transformative enough to justify the lengthy excerpts.

It's a PIA to do, and does little except 1) strip the credit from the source and 2) protect the editor.