Edit in JSFiddle

//extend the B object with Backbone.Events methods
var B = _.extend({}, Backbone.Events);
var C = {}

B.on('logFoo',function () {
    console.log('foo');
},C);

B.on('logBar',function () {
    console.log('bar');
},C);

B.trigger('logFoo logBar'); //logs foo then bar
B.off(null,null,C); //remove all events that have a C context 
B.trigger('logFoo logBar'); //logs nothing, all events that have a C context have been removed