Yes, not only is it possible, it’s happening now.
But they don’t store it ALL forever. They purge after about 3 years if nothing comes up on a particular point of interest.
If they are interested in something, they keep it as long as they want it.
Oh, and it’s been going on for decades.
It used to be computers triggering on “key words” and “key persons” that would initiate a recording. This due to the cost of massive storage for it all...especially before voice was digitized.
But as the internet emerged, so did big bandwidth and cheap, massive storage. They grew up together.
And they just recorded this as I hit enter.
Have you heard about voice to text? That text does not need much room for digital storage. It is also easy to do word searches from text, as you know. Sophisticated software can do complex searches that find people-to-people interactions as well as personal descriptions of selected individuals, such as their health status.