Use callbacks.disable() to disable further calls to a callback list:

// A sample logging function to be added to a callbacks list
var foo = function( value ) {
  console.log( value );
};
 
var callbacks = $.Callbacks();
 
// Add the above function to the list
callbacks.add( foo );
 
// Fire the items on the list
callbacks.fire( "foo" );
// Outputs: foo
 
// Disable further calls being possible
callbacks.disable();
 
// Attempt to fire with "foobar" as an argument
callbacks.fire( "foobar" );
// foobar isn't output