I've amassed many, many hours of these recordings, which provide endless voyeuristic entertainment. 

Back around 2001 there arose a "perfect storm" of technological
innovations which made possible audio files I call "mic in tracks".
This was right around the time that Napster was just beginning to
penetrate into the average computer user's lives.  At the same time,
an audio utility program called MusicMatch Jukebox was also being
widely used, since it was often pre-installed on off-the-shelf PC's.
MMJ allowed you, among other things, to make recordings using the
cheap microphone included with the PC, and save the file in mp3
format.  If you didn't give the audio file a name, it assigned a
default name "mic in track" followed by a number.  Now if you were
also running Napster, and you were careless enough to be sharing
everything on your computer (which *many* were), then anyone also
running Napster could just do a search for "mic in track" and find and
download these personal recordings, usually without your knowledge.

I am that guy.  I've amassed many, many hours of these recordings,
which provide endless voyeuristic entertainment.  Typical recordings
were of people singing, rapping, or playing along with the radio
(often badly), kids practicing their school book reports, audio love
letters, kids being silly, and so forth.  One of my finds was a
14-minute-long recording of a guy praying very fervently and
emotionally, even lapsing into glossolalia.

I've posted many of my favorites on my webpage, for free.  I don't get
a lot of traffic to my site so it's no bother.

http://stark-effect.com/mit.html

The "mic in tracks" are near the bottom of the page-- at the top are
some electronica tunes I created using samples from the mic in tracks.
 It's a hobby.  I'm a university physics lecturer by day, not a
musician, just to give you fair warning.

Hope these files bring you as much joy and wonderment as they've
brought me.  Thanks for doing what you do.