iCloud: Possession Is Nine Tenths Of The Law
An Apple Support Article of note:Â iCloud: What to do with your iCloud data before selling or giving up possession of your Mac:Â http://support.apple.com/kb/HT5189
Take the time to read it and consider all the implications. It’s not an issue of ‘bugs’ but rather that sync can have unintended and unpleasant consequences when it performs exactly as it’s designed to.