As a subscriber to Bob Lefsetz' music newsletter (email), I've often drawn quotes & citations from his missives.
While I've always made it a point to include full credits (i.e. Lefsetz newsletter, and author when it's an outside response), I wonder if this is considered fair use for legal purposes , meaning - not a copyright infringement.
Also, for those who read such posts, do you find it of any interest , does it add anything to a discussion, do you actually follow up or check out these sources?
Myself, I hesitate when "Outside" experts are used to bolster one's case. But there are also references that are used as a basis for threads. I'm sure many remember an amusing series of Rolling Stone lists and reviews that generated much ado about nothing.
Then, of course, in some political discussion threads, Slartibartfast used some numbers from U.S. Congressional records that didn't quite reflect the current memory of certain politicians' historic claims (GOP fiscal responsability vs tax & spend Dems)