köken: From Bär (“bear”) + -en- + Dienst (“service”). Compare Swedish björntjänst, Danish bjørnetjeneste, Norwegian Nynorsk bjørneteneste, Russian медвежья услуга (medvežʹja usluga) and similar forms in other languages. From the French fable L’Ours et l’Amateur des jardins by Jean de La Fontaine, in which a tame bear wants to do his master a favour by hitting a fly that has sat down on the master's…
aile: einen Bärendienst erweisen
Forschung aber, die einer Ideologie dient, leistet der Sache einen Bärendienst.
a poisoned chalice, a chalice that contains a poison · a poisoned chalice (something that causes death or serious harm, frequently initially seen as beneficial)
a disservice, a mistaken kindness, a misguided helpfulness, an attempted favor which turns out to be detrimental, or at least causes more damage than it helps
köken: björn (“bear”) + tjänst (“service, favor”), used since 1891. Compare Danish bjørnetjeneste, German Bärendienst, and similar forms in other languages. From a French fable (L’Ours et l’Amateur des jardins by Jean de La Fontaine) in which a tame bear wants to do his master a favor by hitting the fly who sat down on the master's forehead, but hits the fly so hard that the master too is killed.
köken: bjørn (“bear”) + tjeneste (“service”), with reference to The Bear and the Gardener, in which a bear inadvertently kills his friend when trying to keep away flies. The second sense is attested since 1992, and might be an allusion to the size and (perceived kind) disposition of a bear.