There will be some cases where that's likely to be a slam-dunk. IIRC there were some cases in the western states some years back where relatively small amounts

There will be some cases where that's likely to be a slam-dunk. IIRC there were some cases in the western states some years back where relatively small amounts of drugs (personal-use levels) were used as reasons for seizure of some large farms or ranches. In at least one of those cases I think it would have to be the estate pursuing it though.