meteor $pull ta bort från array

Mitt problem var:jag var tvungen att dra hela objektet:

 Collection.update({"_id":"fTgR2YtHiZBzzqF6J"},
 {
    "$pull": {
        "following": {
            "user": {
                "_id": "MAyxz4Yk5F9vh9RRy",
                "fb": {
                    "id": "100006719587007",
                    "name": "Mary Amfgaiehgkg Smithman"
                }
            },
            "date": "2013-10-11T10:47:58.898Z"
        }
         }
     }
 });

och kan INTE kalla bara detta:

Collection.update({"_id":"fTgR2YtHiZBzzqF6J"},
 {
    "$pull": {
        "following": {
             "user": {
                 "_id": "MAyxz4Yk5F9vh9RRy"
             }
         }
     }
 });