Comment 12 for bug 306438

I agree with the comments in #6, #9, #10 and #11: This is primarily a bug to be
fixed and not just a [Feature] request. The present software makes it entirely
too easy to lose valuable contact data that may be difficult or impossible to
recreate.

As a minimum, a warning dialog should be issued and positive confirmation
required in order to delete a card or list of cards. The dialog should warn
that the delete cannot be undone. I'm uncertain as to whether having a "don't
tell me about this again" checkbox is a good idea, but I tend to think not until
some sort of recovery path is available. The easiest interim implementation (to
patch the bug part of this problem by implementing this without the checkbox.

If some sort of safety fence against accidental data loss is in place, other
nicer options then become feature requests. The checkbox for those who like to
operate in fast-n-dangerous mode is nice, particularly if combined with an undo
operation to correct immediate "oopsies".

I like the idea in #9: Why not treat contacts as being as important as messages?
 When a card is deleted from a normal address book, move it to a "Deleted Cards"
book (creating it, if needed) instead. A lightweight warning could be issued at
this point, with a checkbox for an experienced user to suppress further such
warnings. Cards would only be permanently deleted (with a non-suppressed
warning) when the deleted cards book is emptied or deleted, or when selected
cards are deleted from that book.