If DC is included in the deal (not explicitly excluded = it is included), then it is BA's responsibility and legal obligation. If it's not included, then it's LH's. I really think it's just that simple. They cannot just dissolve DC and hope it will go away unnoticed. Either way, if everyone's points suddenly disappear or are worthless, the responsible party should expect a serious legal challenge. Of course I doubt it will ever come close to getting to that point. I fully expect the lawful owner of DC to make good on the miles. As UK1 points out though, they could attempt to devalue the miles and might get away with it. Depending on how much the devaluation is, it might not be worth it for any given member to put up a legal challenge. If it's a major devaluation though, or the miles are completely erased, I would suspect a number of members to join together and challenge it.