what application are you trying to achieve? Even the example of spying in this article isnt applicable
If I hired a private detective to spy on you, that detective could hide a bug in your home or car, tap your phone, and listen to what you said. At the end, I would get a report of all the conversations you had and the contents of those conversations.
you wont get a summarized report, you get transcripts, you get full emails, you get audio files, if you've ever followed investigations. It's not an impossibly large stack of communication from someone saying or typing a million words a day. It's very easily filterable and searchable.