DBA who is worried reorganizing or rebuidling indexes may cause data loss?
Solution 1:
Rebuilding a database index should not cause any data loss. It will however probably cause a substantial performance degradation as the indexes being rebuilt will normally not be available for use until the rebuild finishes. For that reason it should be done during off-hours when the affected systems are idle.
Paranoia is a Good Thing in a DBA - If they're worried about data loss I would have them do a proper test of the backups (restore them to a separate system and make sure the data is all there), and if they're still concerned then performing a full backup before rebuilding the indexes would be a reasonable precaution to take.
Solution 2:
There is no risk of data loss from rebuilding or defragging indexes.
Solution 3:
Reorganizing the indexes will take less time, and less effort from the SQL server thus they can be done in a weeknight type of instances. If you what you are saying is true, even reorganizing the indexes that have never been, may cause a larger impact on the server as well. Rebuilding the indexes will take a substantial amount of effort from the SQL server since they are dropped and rebuilt. Doing a rebuild on a weeknight isn't worth the risk of the server being busy with indexes and not serving the people using it.
I agree with voretaq7, if he is that worried about working with indexes, try it out on the development or test servers first to see how the react.