In trying to merge lists I accidentally unchecked a list and removed over 6000 contacts from a key, key, key list.
There absolutely needs to be an undo option or button or option to backup the list within the system. It also should warn you that you will be deleting X number of contacts from a list. It did not do this so I had no idea I had mischecked a list. Please add this feature as soon as possible. Thank you!