I was administering a final exam to a programming class. Exam was done on class computers, so with me in the front of the room most of the time I couldn't actually see what everyone was doing (and given the nature of the class, if you cheated it probably wouldn't really help you anyway).
Grading one student's submission, the wording of most of the "essay" questions seemed ... odd. Nothing objectively wrong, but everyone has their own writing style and his answers weren't, well, his. Scrolling thru one particular answer there were some blank lines after the answer ... and then a URL. The URL contained much of the test question. Checking the unfamiliar site, it was a paid technical-question-answering service, base price for answers $30 and rising depending on depth, quality & speed of answer. Copying-and-pasting the purchased answers added the source URL to the selected text, proving malicious plagiarism on the final exam. I figure he spent at least $300 to fail that exam and get one strike per the school's "three strikes and you're out" policy.