From the NYT story seems that PRISM is more b) than a). However, I suppose the remaining questions are:
1) To what extent did these automated processes for reducing the burden of handling FISA requests enable the total quantity of data requested through FISA requests to increase? "Quantity has a quality all its own."
2) How extensive are these broad-sweep FISA requests now, and to what extent do they falsify the impression that FISAs are "lawful, specific orders about individuals" (Google), "orders for requests about specific accounts or identifiers" (Microsoft)? In other words, that each individual FISA request covers only one person or a handful of people, so for example the number of people intruded on by FISAs last year is some reasonably small multiple of 1,856?
3) To what extent could the compartmentalisation of FISA information to a few employees, combined with the streamlining process and broad FISA requests, mean that the CEOs have less awareness than they thought about just how broad the FISA net really casts by now? Or instead are they happy not to know, or happy to be able to pretend not to know?
In other words, is PRISM b) in principle but something closer to a) in practise, and if so who knew?
What are we to believe PRISM is now? Is it
a) a firehose feed that allocates arbitrary, indisriminate, ad-hoc querying over large swaths of user data in cloud datacenters?
or
b) is it an automated system for sending out National Security Letters, and the polling dropbox locations for compliance, and then importing the data into some centralized government intelligence repository?
a) is an absolute outrage, there should be rioting in front of congress and the whitehouse
b) is pretty much just making delivery of information they are compelled to legally deliver more efficient. Although if I were these companies, I'd make it as painful as possible by printing all of the information requested on sheets of paper in Comic Sans and mailing it USPS.