We're not exactly sure what's going on here, but it certainly seems like at least some Google Voice
voicemails are being indexed and made publicly available somehow. If you punch in "site:https://www.google.com/voice/fm/*" as a search string you get a few pages of what appear to be test messages, with a couple eye-opening obvious non-tests scattered in there as well. Dates on these messages range from a couple months ago all the way until yesterday, so this is clearly an ongoing issue -- hopefully Google patches this up awful fast.
P.S. - Google Voice transcription accuracy really falls off a cliff when it's listening to muffled audio, doesn't it?
Google says it's changed how shared messages are indexed
and made available to public searches, so we're hoping this was just a one-time thing.
[Via Boy Genius Report