When angry taxpayers liken the Internal Revenue Service to "vultures," they're actually making a deep linguistic connection.
During the Middle Ages, English officials would charge a tax on non-resident merchants who sold goods on the streets. This duty was known as a scavage (after a Middle French word meaning "to inspect"); the tax-collectors were scavagers.
Over time, those scavagers expanded their duties to cleaning the streets of dirt and debris. Scavager became scavenger, and picked up the senses "junk collector," "garbage collector," and "organism that feeds on refuse or carrion."