I did a BSC in Computer Science at University. About half my class failed our first ever programming assignment because of plagiarism. Loads of people had just shared the code between them, character for character. There were a few cases where they even left the original authors name in the comments at the top of the code.

Instances of plagiarism dropped after that. At least they learned how to change variables, function names, comments and whitespace enough to get around the automated plagiarism detection tool.