It goes on in student newsrooms all the time, but the only time I've ever seen it in real newsrooms is from recently hired students.

It's much too easy a mistake to make, and in some places using "real" text is a discipline offence, so it's much more common to see "cgclcgl" or "hdyhdyhdy" or "123123" or eye-catching text like that. (Lorem Ipsum doesn't leap out at the eye enough).

I once wrote a headline about an invasion of a new breed of octopuses coming to our waters, along the lines of:

"Indian Octopus

Heading Here"

but seeing it on proofs freaked everyone out too much and it had to be changed.