I've had too many personal experiences get messed up just because companies change things on the cloud. I've come to a depressed state of feeling that I own nothing on the cloud and have no ability to keep things working the way they do. Features change and get dropped, things you depend on disappear, etc. And no company will ever take responsibility. It's rare to ever get told what really happened.
Not long after upgrading to Mountain Lion, one of my three primary Google calendars disappeared. It no longer existed. I have multiple Google calendars and some people have read ability while others can create events but I have the sole admin account that could have deleted a calendar. I would never do this, and checked to make sure it's not easy. In fact, a dialog appears telling you to ok that you will lose all your events. I would never do this.
Fortunately, iCal and BusyCal still had copies of this calendar, although they weren't up to date. My wife exported the calendar from iCal and I created a new calendar in BusyCal and imported the events. Not every event was saved, and this led to calendar conflicts of a HUGE magnitude in my life, including hasty rearrangements of my schedule next week and some monetary concerns.
Since I'm the only admin I had two ideas as to what might have happened. Some zealous Google employee might have been looking at my calendars (I wouldn't mind) and accidentally deleted one. Or some hacker got my password and deleted only one calendar. Neither made sense. I did go and install a 2-step security method for my Google account, with odd passwords you never see again generated for apps like Apple Mail and my iPhone Exchange Server accounts and my Android phones. This was also for some apps like BusyCal, but that didn't trigger anything for me right away.
Then last night I got an email from BusyCal saying to basically delete its data before upgrading to Mountain Lion. After upgrading, then you could turn BusyCal back on to do its thing. Click. BusyCal has my Google access and has admin privilege, just as I would. So do these other devices. Something changed with Mountain Lion and BusyCal wound up deleting my Google calendar. This must have happened to other people as well, since I got the BusyCal warning a week or two after the Mountain Lion upgrade.
When I saw how Gizmodo's Twitter account got hacked because some social-engineered illegal access to Mat Honan's iCloud, I thought it was more of the same.