Comment 59 for bug 306438

I have filed a bug that provides detailed arguments why complex UNDO is not good enough (apart from not being realized), and why the simple "confirmation on delete" dialogue would be a good and simple solution to this insidious dataloss problem:

Bug 650789 - Please add a "confirmation on delete" dialogue for address book entries ("Are you sure you want to delete the selected contact(s)?")!!!

This bug was duplicated against
Bug 526541 - Please add a "confirm on delete" option for address book entries...
That bug starts out from the somewhat vague case where, with focus on the main addressbook's contact list, user types the initial letters of a contact and then wants to delete the last character of that invisible search sequence.

So the discussion on confirmation-on-delete is now going on in bug 526541. Don't forget to vote for those bugs if you like the idea, and prefer a quick fix that could actually happen over a promised complex fix (this bug) that hasn't happened for the last 10 years, and seems unlikely to happen anytime soon, given that it is currently assigned to nobody.