xD Yah, everyone has an ID. It's most easily seen from a gallery or shop opened by the user - it'll be at the end of the url.
Or you could ask Suga how to see it.. and spend the next week going through her ridiculous process. Hurr.
That does bring up a good idea though. Sorting by ID (if the list doesn't already) would prob'ly be a lot less glitchy and full of exceptions, and it would still be sorting by join date.
If it does happen to sort by ID already, then.. well. Nevermind. o3o