Aggressive Orcas Sinking Boats off Iberian Coast Puzzle Researchers

A group of three orcas in the Strait of Gibraltar have sunk three boats in the past three years.
Researchers believe the behavior may have started with an orca nicknamed White Gladis who had a traumatic experience with a boat.
The behavior seems to be spreading through social learning to other orcas in the population.
While some experts think the behavior is playful, others believe it is purposeful and aggressive.
The orca attacks do not seem motivated by revenge or aggression toward humans.