filterBy with boolean field is not working for me

$scope.users = [
{ id: 1, first_name: 'Rob', last_name: 'John', mobile: 4444, isFoo: false },
{ id: 2, first_name: 'John', last_name: 'Wayne', mobile: 3333, isFoo: false },
{ id: 3, first_name: 'Rob', last_name: 'Johansson', mobile: 2222, isFoo: false },
{ id: 4, first_name: 'Mike', last_name: 'Terry', mobile: 1111, isFoo: true }
];

Return users whose `isFoo` is true:

{{ user.id }} : {{ user.first_name }} {{ user.last_name }}

Result:

All users... why?