It should be noted though that extended quotes, properly sourced, are not generally a violation of copyright.  I'd like to see a few examples.  We have never, to my recollection and knowledge, had a legal complaint or threat of any kind about a properly sourced quote.  There could be exceptions such as quoting the entire lyrics of a poem or song in a single block quote, but that isn't what we are talking about here.  We're talking about a block quote of a passage from an academic paper published behind a firewall by Elsevier.  I find it very hard to imagine a serious legal issue with that.