Demand for self-defense items such as pepper spray, batons and whistles have spiked in the wake of a recent spate of indiscriminate attacks in South Korea. Online transactions for self-defense equipment shot up 399 percent for the period of July 21 to Aug. 3, from a month earlier, according to Interpark Commerce. Items for sale on the e-commerce platform include expandable batons, pepper spray and brass knuckles. The...