If it's `{id: threadId}` the condition [here](https://github.com/rwaldron/gaia/blob/v1.3-drafts/apps/sms/js/drafts.js#L125) will be falsey because the id is defined. Then it will try to search through the array, update the index, then remove only the draft (on L136).

If the draft id is not defined, it will zero out the entire array, which is what we want because we don't know the id of a draft on another thread (or if we do I don't know how to get it easily). 

The above is my understanding of `Drafts.delete()`, not gospel. So I may be wrong. :)