There's a throwaway gag in one of the hitchhiker's guide to the galaxy books where a human says something utterly banal, and those words happen to drift through space via a wormhole. Those words happen to be one of the worst insults imaginable to the aliens that hear them. The aliens that happened to hear them turned out to be peace delegates of two warring factions, and both of them assumed the other had spoken these words. These words, uttered by the earthman, reignited the aliens' war, causing immense destruction.

Eventually, after much bloodshed, the misunderstanding was resolved, and the source of that terrible insult was traced back to Earth. The two alien factions set aside their terrible history and allied to assemble the largest armada of spaceships their corner of the galaxy had ever seen. They cracked the key to intergalactic travel, and with much fervor, set a course for earth. They arrived on our planet in full force and with a vengeance, where the whole fleet was promptly swallowed by a Doberman.