Put auth-token on all jQuery Ajax requests.

_jquery-auth-token-django.js

$(function() {
  $.ajaxSetup({
    headers: { 'X-CSRFToken': $('[name="csrfmiddlewaretoken"]').val() }
  });
});

backbone-auth-token-django.js

// Not really recommended, since Backbone relies on jQuery for Ajax anyway
var sync = Backbone.sync;
Backbone.sync = function(method, model, options) {
  options.beforeSend = function(xhr) {
    xhr.setRequestHeader('X-CSRFToken', $('[name="csrfmiddlewaretoken"]').val());
  };
  return sync(method, model, options);
};