How to lock data after publishing the course.

I want to know exactly how the data can be locked. So that data can not be copied/download after publishing.

Real locking is impossible. All data is stored in files, most as xml but it can be read anyhow.

Some whizzgirl/guy could try to block caching etc, but other whizzkids could break it.

If it's published onto a CD then shred the CD.
If it's on a server then delete the files and wipe any backups.
The harsh fact is that it is extremely difficult to secure data. Once it is published somewhere then it can be copied.
Even if you made the files into an encrypted zip it is still vulnerable once that has been opened by a viewer. Also as it is web based the browser can retain a local copy of the page or pages so again once viewed it is open to copying.