marker data - AngularJS Google Maps Directive

<!DOCTYPE html>
<html ng-app="ngMap">
<head>
<meta name="viewport" content="initial-scale=1.0, user-scalable=no" />
<script src="https://maps.google.com/maps/api/js?libraries=placeses,visualization,drawing,geometry,places"></script>
<script src="https://code.angularjs.org/1.3.15/angular.js"></script>
<script src="https://rawgit.com/allenhwkim/angularjs-google-maps/master/build/scripts/ng-map.js"></script>
<script>
  angular.module('ngMap').controller('MyCtrl', function() {
    var vm=this;
    vm.data =[
      {foo:1, bar:1},
      {foo:2, bar:2},
      {foo:3, bar:3},
      {foo:4, bar:4},
      {foo:5, bar:5},
      {foo:6, bar:6},
      {foo:7, bar:7}
    ];
    vm.positions =[
      {pos:[40.71, -74.21], name: "dave 1" },
      {pos:[40.72, -74.20], name: "dave 2" },
      {pos:[40.73, -74.19], name: "dave 3" },
      {pos:[40.74, -74.18], name: "dave 4" },
      {pos:[40.75, -74.17], name: "dave 5" },
      {pos:[40.76, -74.16], name: "dave 6" },
      {pos:[40.77, -74.15], name: "dave 7" }
    ];
    vm.showData = function (marker, param){
      console.log(marker) //WHY IS MARKER BEING PASSED THROUGH?!
      console.log(param.name);
    }
  });
</script>
</head>

<body>
  <div ng-controller="MyCtrl as vm">
    <ng-map zoom="11" center="[40.74, -74.18]">
      <marker ng-repeat="p in vm.positions"
        position="{{p.pos}}"
        on-click="vm.showData(p)"
        title="pos: {{p.pos}}"></marker>
    </ng-map>
  </div>
</body>
</html>