What is the difference between Elsevier's 'waterfall system' and 'cascading peer review'? A lot of people are grumbling about USPTO 9,430,468, "Online peer review system and method", which describes (if I'm reading it right) Elsevier's system of reallocating papers rejected from Journal A to a potentially more suitable Journal B. Parts of the patent describe the general process of peer review and (partly because of this) some of the criticisms currently circulating seem to think that this is a patent on the process of online peer review itself, which would clearly be ridiculous. However, the Electronic Frontier Foundation has picked this as its 'stupid patent of the month' for August, pointing out various examples of a similar process called cascading peer review dating back to at least 2009 (example 1; example 2). Eff clearly has concerns about the novelty of this patent.

My question: what, if any, are the differences between Elsevier's now-patented 'waterfall system' and 'cascading peer review'?

(I'm not sure if this would be a better fit for Law.SE, but thought the audience here would be more familiar with the important areas of the peer review process)
I managed to get some more information on this from William Gunn (@mrgunn), Director of Scholarly Communications at Elsevier. So not an official legal statement from a patent lawyer, as he notes himself, but a plain-English explanation from someone familiar with publishing and who has had a chance to ask the people involved, which is pretty much everything I could have wanted. Short Twitter-transcript follows (stripping out Twitter tags; otherwise as written); I'll probably try to come up with a better way to format this later.


@MrGunn: "The Elsevier legal team says this just covers our
implementation &amp; is defensive."
(https://twitter.com/mrgunn/status/777989863748448256)
@MrGunn: "IOW [in other words], not to be used to sue anyone else, just to prevent us
from getting ripped off"
(https://twitter.com/mrgunn/status/777990251667087360)
Me: "Thanks, that's helpful. So what makes system distinct? How do
you tell if ripped off?"
(https://twitter.com/arboviral/status/778146459044745217)
@MrGunn: "(making room) It's common for software companies to patent
their implementations of a more general process. That's all this is."
(https://twitter.com/mrgunn/status/778269748236685312)
Me: "thanks - that helps. So it would only be enforced if someone
literally copied the Elsevier code and tried to pass it off as
theirs?" (https://twitter.com/arboviral/status/778497951232618496)
Me: "Well, not necessarily line-for-line, but if you had reasonable
suspicion that they'd used the Elsevier system as a starting point?"
(https://twitter.com/arboviral/status/778498336156418048)
@MrGunn: "Enforceability of software patents is not a subject I know
very much about, but I would guess so."
(https://twitter.com/mrgunn/status/778606526160175104)


So it's not intended to cover the general process of cascade reviewing, but only the specific implementation used by Elsevier.