This new 27" iMac was sitting on the floor in the box it came in since it arrived four months ago because, although feeling it was time to upgrade, I dreaded the switchover from my perfectly good mid 2010 model. Migration assistant worked seamlessly but I have been dealing with the usual nonsense with resetting, putting in passwords/codes for all the various apps, on line accounts, etc, etc. just as I had expected. Yesterday, tired of looking at the red slash over the preferences icon in the dock, I entered my apple ID password into iCloud; BIG mistake. This morning when I opened "contacts" I panicked; thousands of entries have disappeared, leaving only a handful contacts. WTH? How do I get my contact data back? Help would be very much appreciated!