When I call within a ng-repeat group
Delete
the remove function is
You shouldn't use curly braces in the ng-click expressions. Try this instead:
<span ng-click="remove(user.id)">Delete</span>
And be sure to check the AngularJS expressions documentation: http://docs.angularjs.org/guide/expression
ng-click="remove(user.id)"
should work, ng-click evaluate it content so you don't need interpolation