Hi, I have just sold my Macbook Pro. I used Migration Assistant to transfer to my new mac which went fine. I did the usual signout of icloud, imessages, deauthorise itunes etc.. Then used Disk Utility to erase (which took only about a minute for 100GB of data!) and selected to reinstall el capitan (which took about an hour) Just before selling, the mac loaded to the set up screen (e.g. enter your country, keyboard selection) Does that mean all my data was successfully deleted?