Plagiarists caught by peers

A post titled Why Students Who Plagiarize Get Away With Nothing contains the text

Coursera is the online venture that has partnered with Stanford, Princeton and other elite institutions of higher education to offer web versions of popular courses to the public. The instances of plagiarism, which apparently occurred in at least three Coursera courses, were discovered by fellow students engaged in "peer grading," evaluating their classmates' assignments. The professor teaching one of the courses posted a message imploring his students to stop copying others' work without attribution.

One recalls that Joe Biden's plagiarism at Syracuse Law School was initially snagged by a form of peer grading.