It's been in use since at least 2006 that I know of. That's when I was first let onto it by a friend running a big content farm. Now it's absolutely out of control. I use it myself generously to help me write articles, but you have to be incredibly careful because it so frequently hallucinates. You have to have some knowledge of the domain you are writing in to peep when it is going full HAL9000 on you.
The Internet now feels like this to me:
https://www.okcu.edu/admin/communications/web/wharrgarbl
See also:
https://en.wikipedia.org/wiki/Dead_Internet_theory