I have never encountered this personally, but helped a few. There could be variations of what to expect, in response to your question. YMMV: * If using the Web

I have never encountered this personally, but helped a few. There could be variations of what to expect, in response to your question. YMMV: * If using the Web UI, it will be locked & probably will remain in some catatonic state, until Apple restores or purges its contents. The ID will not be reissued to anyone else, so it is a safe assumption no one will get any email, notes or photos that belonged to you. Apple support page will still be available in many cases (and probably the only thing) when you try logging-in * On your device, syncing will stop. Local content will remain. Shared albums might disappear or seem broken i.e thumbnails will be visible but suspended account will not be able to fetch data. App purchases will stay but updates will probably be infeasible. iCloud dependent document access will definitely be broken.