Comment by bogzz

For what it's worth, this is anecdotal as well, but a close friend of mine teaches math at a community college in NM and he routinely catches most of his students cheating on online multiple choice tests like this. He adds a sentence in white and tiny, tiny, text to the questions that either flip their meaning entirely or simply make one of the wrong answers seem correct. When I was visiting him at the end of last semester he was quite depressed when ALL of the students in one of his classes were caught cheating like this.