I had a prof that did something like this. It was back in the 80s, so no internet. Instead, because it was a large class, he had to give the mid-terms to different parts of the class. He would make all the tests look similar, but with small differences. If the right wrong answers turned up, he would fail the student. (I hope that makes sense.)

At the end of the semester, he explained what was going on. The course was required for the degree (EE), you had to have a C or above to pass, and it was a bear. He said right out, the course was designed to cull the heard.

A few students were outraged. I'm not surprised by the reaction Merriam got. Speaking for myself, I was indifferent to what he had done, though I didn't speak up. I think he should ask the students that he determined hadn't cheated what they think.