Three identical -- WRONG answers.
Three grades of 0 in the on-line grade book.
Two bounced e-mails.
Two seemingly innocent questions about why their grade is "not showing up" on the class discussion board.
Two replies of "we need to discuss your exam in private" -- from me.
Hmmm..... I've given them until Monday to figure it out.
Tuesday I'm in surgery and won't deal with this for a month.
If I can't communicate with them, in person, by Monday afternoon the grades stand.
My best bit of advice for logic cheaters is to copy from someone who actually knows how to do the work. That way, your answers won't be uniquely bad.