Discussion: Avatar URL Expiry

How long are avatar image URLs valid for? When you change your appearance, the old avatar images continue to be accessible - do they ever get tidied up and disappear, or can we assume they will remain in existence for ever?

What about the spritesheets?
David: As of now, we keep them around indefinitely - but we will probably purge older ones someday. I wouldn't recommend relying on them as there are no assurances that they will stick around forever.
Thanks Brady. I assume they'll likely stick around for a 'reasonable' time though. i.e. if someone updates their wardrobe, the old images aren't purged in the immediate aftermath.