It is a contrived example that just looks at electron drift velocity. If you looked at how fast an electron travels in a beam, inside a cathode ray tube (like in a pre-LCD screen color TV), you'd find that the electrons move at astonishing speeds. Basically, an electron traveling through a 1 Volt gradient, picks up a speed of 600 Kilometers/second. The typical color TV cathode ray tube applied an accelerating voltage of 100,000 Volts or more, so you can do the math. Go further and put the electrons in a beam, inside a particle accelerator and they easily achieve relativistic speeds (speeds just a few percents below the speed of light).