Tuesday The Intercept explained How the NSA Converts Spoken Words Into Searchable Text "Top-secret documents from the archive of former NSA contractor Edward Snowden show the National Security Agency can now automatically recognize the content within phone calls by creating rough transcripts and phonetic representations that can be easily searched and stored. The documents show NSA analysts celebrating the development of what they called “Google for Voice” nearly a decade ago."
So it's probably ok (at least to us) that they do this for foreign phone calls. It's debatable if it's between a US citizen and a foreigner but we know under current guidelines the NSA would say that's fair game. The problem is, they're doing this not just for traditional phone calls but also for voice over the Internet, for example, Skype and probably most other popular VOIP systems. So once you accept that they do that (which makes sense because traditional phone use is declining) I'm sure they start to argue that it's difficult to intercept voice communication knowing that it's not purely domestic, so they collect it all and only scan what they need. Or maybe they have a computer scan everything and only report calls that have at least one foreign endpoint, unless they're really suspicious or something. So now you have to assume they're collecting every "voice call on the Internet". Are you ok with that? Are you okay with that program being authorized in secret, with no serious oversight?