Plagiarism

[dposborne]

plus 1. Unless you're spending your time collecting evidence (which might make it look like you have something against these students) you have no proof and can potentially ruin these student's academic career. This isn't just an issue of telling, this is a very serious issue. Furthermore, you don't know that the instructor isn't aware. The instructor may be collecting documentation but needs more; which would be shortened by your intervention.

Per EC's policy on Academic Integrity:

..."Students also have an ethical obligation to report violations of the academic honesty policies they may witness."

Excelsior College | Academic Honesty