Training modules/Dealing with online harassment/slides/understanding-actionable-versus-non-actionable

Investigating reports: Understanding "actionable" versus "non-actionable"
Not everything you investigate will ultimately turn out to be actionable. Even in situations where wrongdoing is confirmed, you may simply not be able to take measures against the reported user. For instance, if an attack has happened on social media and you are unable to reasonably connect the social media account with a Wikimedia one, you may have no options for on-wiki action. In other cases, the target may have been subjected to negative treatment by another editor, but the actions don't meet the standard for harassment or rise to a level that merits action under local policies and guidelines.

In such cases, the best of your available courses of action is not to punish the alleged attacker, but rather to provide support to the reporter. Keep in mind that not taking action against a reported aggressor doesn't mean the reporter was necessarily wrong to report this as harassment. Nor does it mean the report was inaccurate, or that either party is totally innocent. A "non-actionable" report is not the same as a false report – it is simply one that you cannot take direct action to resolve.