Cheating is theft from honest students. Cheating is a serious crime, and one of my responsibilities is to detect and punish this crime.
Please vary your exam seating, and do not sit with study partners. When students sit next to each other on multiple exams, I study their exams for copying. It is your responsibility not to create the impression of copying.
I am scanning all exams throughout the semester. Now, whenever an unusual error appears on exactly two exams, I can easily execute a shell script to compare both students problem by problem for the semester.
When I detect copying, I submit a final grade of AR and file a complaint. The AR will likely lead to a grade of F, and the complaint may lead to expulsion.
In summary, my class is a poor risk for cheaters, because I look for cheating, I detect cheating, and I am good at what I do. If you are tempted to cheat, do not be lulled into a false sense of security by your experiences in other classes or the apparent ease with which you can copy during our exams. I will give no indication that I have detected copying until final grades are submitted, and it is too late to withdraw from the class.