This is an old revision of the document!
Start with this:
curl 'https://plus.google.com/_/stream/getactivities/112121758194167388066/?sp=\[1,2,"112121758194167388066",null,null,null,null,"social.google.com",\[\]\]'
Round out some glaring omissions
Maybe use https://www.greplin.com/ to search them all?