For example, you could make an un-clonable hard disk: the hard disk would act normal if the access pattern for the sectors was somewhat random, like a normal OS would access a filesystem. If the disk was accessed only sequentially, like a disk cloning utility would do, the hard disk could mangle the data, making the clone different from the original.

That’s pretty nasty. Imagine having hard drives that, when law enforcement/forensic data recovery firms try to image them in a “read-only” configuration, end up spitting out random garbage while simultaneously zeroing out the actual data on the drive. The evidence returned is useless and the LEO/recovery firm has actually trashed the physical drive.