We can avoid an indentation in this whole block if we do:

```javascript
var lockKey = loginId.externalId;
Locking.acquire(lockKey, 15, function(err, lockToken) {
    if (err) {
        return callback(err);
    } else if (!lockToken) {
        return callback({'code': 400, 'msg': 'Could not get lock for ' + lockKey});
    }

    // Make sure the loginId...
```

Also, the error shouldn't say something about a lock key because that's way too low-level to be sent back to the user. Makes more sense to use: `{'code': 400, 'msg': 'This login id already exists and is already associated to a user'}`