Coastal Florida towns are playing hot potato with spring breakers who use social media to organize “takeovers” of gatherings by drunken flash mobs, leading to violence and mass arrests. Cops locked down Daytona Beach this week after a string of shootings and a beach “takeover” that ended in a mass stampede of high-school and college students fleeing for their lives. That single “takeover” resulted in 133 arrests and prompted authorities to turn the entire beach into a party quarantine zone, with doubled fines for citations and strict limits on gathering sizes, according to the Volusia County Sheriff’s Office. Daytona had...