Comment 2 for bug 1263378

Yes, friends backend parses the headers (at least for Twitter) and then enforces them in a gentle way, introducing short pauses in order to avoid going over the limits.

Unfortunately one of the limitations of the frontend/backend architecture we're using is that we really don't have a good communication channel for signaling errors to the user. Part of the reason for this is that the backend is expecting to have multiple frontends (eg, the Social Scope, the Friends App, we were hoping many apps would begin integrating social network feeds from the same backend), so there's no real way to say "display an error in the friends app" because as far as the backend is concerned, there's no way to know which frontend is running (if any).

To properly resolve this bug, friends backend is going to need some kind of error-message-db (similar to the existing DeeModel used for tweets) but existing separately, in parallel to the original. Then various frontends like Friends App and Social Scope can listen for callbacks on that model to know when to display a notification/error message.

We already had a plan to implement something like this, but it just fell on the backburner as other projects became higher priority for Ken and I.