We all have heard about hackers - computer experts who have used their power to gain access to systems that they were not authorized to access.
Most hackers are quite harmless.
But harmlessness aside, hacking is a crime. In either case, the hacking must be intentional. You must mean to cross a border for your crossing to be a crime. That does not mean you have to intend to cause harm before your crossing is a crime. Morris intended his worm to gain unauthorized access to machines around the world, but he did not intend the worm to do harm.