@verius @nerthos A desktop computer is less harmful grounded through the case because it's usually sitting on the ground, but a computer grounded through the case becomes 100% less safe if it's not, hi laptops, or cases with those little rubber feet.

Here in Canada (or back home in britain) it is an electrical standards requirement any device that is not double insulated must have a ground pin.  Double insulated devices are defined by both line (positive) and neutral (negative) being completely shielded from outside contact.  So both the supply and return rails of the circuit have to be insulated.  If you're grounding to the chassis, you automatically fail this requirement.