In the National Review, there is a story that the DOJ judge-shopped in order to find a judge who would sign a warrant for Rosen.
The 1978 Foreign Intelligence Surveillance Act, Section 103(a) reads:
The Chief Justice of the United States shall publicly designate seven district court judges from seven of the United States judicial circuits who shall constitute a court which shall have jurisdiction to hear applications for and grant orders approving electronic surveillance anywhere within the United States under the procedures set forth in this Act, except that no judge designated under this subsection shall hear the same application for electronic surveillance under this Act which has been denied previously by another judge designated under this subsection.
Notice the bold above. Seems to me if the judge-shopping charge is true, the DOJ broke the law.