The old parts of the WaPo's notes don't seem to have been revised. For example, the 'PRISM' name probably doesn't have anything to do with fibre-optic taps, since the You Should Use Both slide indicates that the PRISM name refers only to the Web-company "direct collection" operation rather than the "upstream collection" from the network. https://news.ycombinator.com/item?id=5887627 (This Washington Post page still doesn't seem to have any mention of the You Should Use Both slide, probably for the bad reason that it was the Guardian's scoop.) Similarly, the Introduction slide seems to be mostly relevant to upstream collection rather than PRISM.