Just wan't to add that I etiher got hacked for the third time or that apple just reset my password again as a countermeasure to another break in attempt.
Fortunately i deleted my contacts list in iCloud after the first go and there are no e-mails in the sendt folder in iCloud so I guess nothing big has really happened but something fishy is going on.
I'm a PC user but I have an iPhone 4 and the iPad 3 - I have no real basis for saying it but i DO have feeling that there either is a vulnerability within the iOS software that somehow reveals the iCloud login info - or that the iCloud service it self is vulnerable to attacks.
I've mentioned it earlier and it could be espcially crafted websites that do this, specific apps (although that seems less likely, in my case, becuase I only have the most common apps from "big" developers like Google, Facebook and some of the more popular games.
Maybe the iOS devices can even be exploited by devices on the same WiFi as them - who knows .. but my feeling is that somewhere out there is an exploit that is being actively used either against our devices or against the icloud service.
Just to recap - my account was first hacked on the 16th, then I had to reset the password again on the 17th and now yet again today.
I contacted an apple rep who gave me his contact details and told me they would monitor any activety closely - so for all I know, the last two password resets could be Apple's countermeasure to some sort of brute force attack against iCloud or whatever.
I will keep on bugging him for as long as this issue continues but as of now he has yet to reply to any of my e-mails, maybe I'll hear something tomorrow because of the weekend but as of now I DO NOT FEEL SAFE with the iCloud service as it is now and personally I have deleted EVERY photo and document and contact that has been backed up there - its probalby been stolen already - but there is no point in keep on using a cloud service that has obvious security issues.
Also, the MO in my account were as described by many others here. mails in my sent folder went to three of my contacts every time until everyone in my contact list was spammed .. this is something I'm NOT very happy about!
Deleting contacts and data from iCloud ASAP is the best advice I can give for now - and lets hope Apple steps up their security game (and information flow for that matter) to better help us understand what has happened, how and what countermeasures are being put into place..
Also, please add a way to see when the last log in time was and from what IP it originated ! that would indeed be helpful!