Rauch V. Day And Night Manufacturing Corp‪.‬

The single issue in this appeal is whether a district court may sua sponte dismiss a diversity action against defendants for lack of personal jurisdiction over them where the defendants themselves have waived any objection on this account and have acted in the case inconsistently with that defense. We hold that it may not and that the district court here erred in granting relief which the defendants themselves were precluded, under Rule 12, Fed.R.Civ.P., from seeking.