Accidental harm is harm resulting from unforeseen effects of attempts to do good.

Further reading

Aird, Michael (2020) Information hazards and downside risks, LessWrong, February 18.

Dalton, Max & Jonas Volmer (2018) How to avoid accidentally having a negative impact with your project, Effective Altruism Global, October 27.

Hilton, Samuel (2019) Managing risk in the EA policy space, Effective Altruism Forum, December 9.

Kokotajlo, Daniel & Alexandra Oprea (2020) Counterproductive Altruism: The Other Heavy Tail

Wiblin, Robert & Howie Lempel (2018) Ways people trying to do good accidentally make things worse, and how to avoid them, 80,000 Hours, October 16.

Wikipedia (2002) Unintended consequences, Wikipedia, October 1 (updated 20 April 2021).
See in particular, "Unexpected drawbacks" and "Perverse results", not "Unintended benefits".

differential progress | information hazardspillover effects | unilateralist's curse