(I can't mention cheating without thinking of the New England Patriots, who just had their perfect season ended by a surprise loss in the Super Bowl. Woohoo! It's pretty awesome that in one game, their legacy went from best-ever to most-embarrassing-and-painful-loss-ever. There, got that that out of my system, now on to the actual post.)
As part of my graduate school work, I grade homework assignments for an undergrad class. It so happens that the homework problems for this class are exactly this year as last year. It also happens that, for one week's homework, the official answer sheet (for last year and this year) includes a mistake.
Would it surprise you to learn that roughly two-thirds of the class wrote down not the right answer, but the exact same incorrect answer which was on the answer sheet?
It's clear to me that all these students possess copies of the answer sheet from last year, and they are copying from it instead of doing the problems themselves. I even saw one student's homework, on which he wrote down the correct answer, but then apparently modified it in each of the last four steps to make it look like he honestly got the official (wrong) answer.
The problem is, since I have no proof than any of these students didn't just make a stupid mistake, there is nothing I can do about this apparent cheating.
I guess it's unrealistic to expect that cheating is any less pervasive here than in the US... but still.