Most colleges have some sort of honor code by which students agree not to plagiarize, copy, use cribs or otherwise cheat.
I think that simply saying "no cheating" is adequate. Every semester, I had students cheat on the final exam. I tried to catch someone in the first final, as that spread the rumor that I was actually paying attention, and fewer people would cheat on test in the following days. Cheating always took the same form: a cribsheet hidden under the final exam. There are more sophisticated ways to cheat (soda bottle labels, MP3 files, cellphones) but I never ran across any of them
I just gave them a zero on the final and averaged the grade. It nearly always added up to an F.
Parents suing the school district for expelling a student from an AP class is absurd. What motive would the school have to falsely accuse the kid of cheating? There is always evidence.
My office mate taught English, and had to give a term paper. Whenever she would suspect some student of plagiarism, she would read me a sentence. A Google search would invariably turn up the entire paper, verbatim. There is also a website called turnitin.com. Students were told of this website in advance, and it was mentioned in the course syllabus. The instructions were to submit the term paper BEFORE handing it in to see if it was plagiarised. More than 10% from any one source would return the message that it was requested to rewrite the too extensive quoted portion. Many students never bothered.
But as it was mentioned in the course syllabus that this was required, and as every paper was submitted in printed and word processing file format, it was 100% certain that plagiarism was found.
