Some of the lower division classes with large numbers of students use a voting system for in-class feedback. Students register these devices and then respond to professor questions. Computers tally attendance, grades of in-class assignments, and levels of engagement among other things.
This is a version of a device:
Someone repeatedly tampered with the system at a State university, the professor noticed, and the University PD discovered who it was through video surveillance. The student was subsequently given a failing grade, ejected from the class, and suspended for a year from the university - as well as being criminally charged.