[woodruffw]

Not without false positives, which are unacceptable (unless you're willing to put the work saved from plagiarism checking into absolving the innocent).

I was forced to submit essays to a plagarism checker in high school (well over a decade ago). The company running this checker had, in their infinite wisdom, included a check for writing complexity under the assumption that a 10th grader who writes like an adult is probably cheating. This was embarrassing for everyone.

[yowzadave]

I had a high school English teacher who became suspicious of a piece of writing I did for this reason—no automated checking was necessary! he called me in to talk with him about the work, probed my knowledge a bit, satisfied himself that it wasn't plagiarism, and gave me a compliment for writing at a high level.

False positives are not necessarily deal-breakers, as long as the teacher treats the situation carefully before taking any disciplinary action.