or failed to ‘exercise its authority when it was its duty to do so.’” Id. at 159 (alterations omitted) (quoting Richardson Greenshields Secs., Inc., 825 F.2d 647, 652 (2d Cir. 1987)). The filing injunction barred Noble from filing civil rights complaints in the United States District Court for the District of Delaware without that court’s prior approval, and Noble has not established that his action was improperly dismissed under the filing injunction. Noble also contends that he is entitled to a writ of mandamus forcing Judge Robinson to recuse from his “hybrid” lawsuit. Initially, we construe the District Court’s order dismissing his civil rights claims as effectively severing those claims from his habeas corpus claims. See White v. ABCO Eng’g Corp., 199 F.3d 140, 145 (3d Cir. 1999) (<HOLDING>). Given the differences between petitions for
holding that under current eleventh circuit rule the failure to object limits the scope of our appellate review to plain error review of the magistrate judges factual findings  however failure to object to the magistrate judges legal conclusions does not preclude the party from challenging those conclusions on appeal holding that failure to object to magistrate judges recommendation waived issue on appeal recognizing that the magistrate judges actions effectively severed claims against only certain defendants holding that district judges power to review magistrate judges actions prevents article iii from being undermined by such delegations holding although petitioner did not object to magistrate judges failure to address certain claims in petitioners  2254 habeas petition we nevertheless could review de novo whether the district judge had violated clisby