For as long as humans have painted fences and coated bridges, rain has been understood as a slow, patient adversary — wearing surfaces down through friction and chemistry. Researchers at the Max Planck Institute for Polymer Research have now revealed a third and previously unrecognized way water destroys protective coatings: electrically charged droplets, accumulating thousands of volts simply by sliding across surfaces, discharge into coated metals like miniature lightning strikes, punching microscopic holes that invite corrosion to take hold. The discovery reframes something as ordinary as r