Dolphin Attacks Spoil Summer Along a Stretch of Japanese Beaches

It is revenge for Taiji dolphin drive hunt

But in many cases, beachgoers were bitten when they approached or attempted to touch the dolphin,

Well no shit. People do this exact thing all the time, including in America. That's how "ooh look at the cute fuzzy baby bison" turns into "Tourist treated for multiple broken bones."

Maybe they wouldn't be sexually frustrated and aggressive if they weren't all caged up.