I have no idea how most of my contact got on my mac in the contacts book , they're in groups some as well. Is there any way I can delete them with a program for mac only I have tried deleting them fom my iPhone with an app and they were deleted from iCloud but no way will they go from my macs contact book. I've tried manually deleting them by highlighting and pressing the backspace key on my mac but it just won't allow me to , either one by one or as multiple deletions . Can someone help me please.