CS was a popular elective in my school (class of 2002). Full copying and pasting of programs, including the comments was routine for nearly the entire class. Even interested students such as myself (I had had some programming experience at a...computer camp in junior high), didn't really have the opportunity to learn anything from the teacher or write programs because of the attitude in the class. Of note, there were a lot of gifted & talented / AP / whatever students in the class that actually had rather high academic achievement in high school but the class had become a such a joke that even they copied and pasted the programs.
Of course, this is an isolated school. I'm sure things go differently in different schools, but I am sure code plagiarism (is that even the right term? I am not a programmer by trade) is fairly common when you get a high school teacher that is teaching out of the book and doesn't really care about the source codes as long as the programs compile and she can check the "pass" box in the grade book for the assignment.
We actually learned some true basic when I was in 4th-6th grade as a part of the gifted curriculum, and I received far more teaching at that time despite it not even being a full CS course...probably because the teacher actually cared.