Condition #7:
As noted above, the permissibility of speaking negatively for a constructive purpose is based upon the principle that it is not lowly to relate negative information for a positive reason.
This applies only to information which is derogatory but harmless. However, it is forbidden to relate harmful information for a constructive purpose. The only exception to this rule is where one has determined that halachah allows for the subject to be harmed in that manner.