tbf, throwing things and little or no crowd control have been around ever since pop concerts became a thing, e.g. shee the Stones at Altamont, or even the Blues

tbf, throwing things and little or no crowd control have been around ever since pop concerts became a thing, e.g. shee the Stones at Altamont, or even the Blues Brothers "Rawhide" scene. And people getting shots during public appearances, again, was a thing even before Lincoln. Mass shootings are definitely a new phenomenon though.