How do I find my iCloud data that Yosemite erased ?? Yosemite has resurrected an old Apple ID from the Me days. Everything is gone because of Yosemite

Question

How do I find all my data on ICloud. I downloaded Yosemite and it erased ALL of my data on the Cloud. It caused an Apple ID from Me to resurrect and has wreaked havoc on my devices. It even erased all my backup data on my Passport drive. The Passport drive shows all of my downloaded backups from 2011, but when you double clickon the various backup dates, they all show as empty. I was able to restore my music by downloading a 3rd party application, but my pictures are gone. I was having a conversation thisweekend and an eavesdropper said she has the EXACT same problem.

Answer 1

An apple ID is nothing more than a "User ID"
Actually, it is more than that. If you read the licensing agreements for any OS version or app obtained at the app store, it will become clear: the license for any app or OS obtained at the app store is not transferable. Hence it is tied to your Apple ID and will remain so - it cannot be removed.
You are supposed to remove anything obtained at the app store from the computer before giving/selling it. Your father will also not be able to reinstall the OS if need be.
Which OS version was on the Mac originally? You will need to use internet recovery (Command + Option + R) to erase your drive and then reinstall the original OS (if Lion or later). If it came with an install DVD, boot from that, erase the drive and reinstall. After that, your father can very easily download/update/reinstall any OS or app using his own Apple ID.