What is the purpose of a safety wire through a turnbuckle used to tension guy lines?

Turnbuckles are used to adjust the tension on guy wires that support an antenna tower. Wind and tower movement cause continuous vibrations that can slowly unscrew the threaded ends of the turnbuckle over time, loosening the guy wire and compromising the tower's stability. A safety wire is routed through the center body of the turnbuckle and the eyes of the end bolts to physically lock the components in place, preventing this accidental rotation. Distractors suggesting the wire is for lightning grounds or structural backup are incorrect because safety wire is far too thin to carry heavy tower loads or massive electrical currents.