District court had jurisdiction over subpoena for communications to US firm from foreign client, as jurisdiction arises from the present location of the documents, viz, midtown.
Court abused its discretion in issuing subpoena in furtherance of a foreign court proceeding for communications with a foreign client previously released under confidentiality order, as the documents would not be available in the foreign forum, and the party requesting them is a party to the foreign litigation. Disclosure would undermine confidence in the confidentiality of attorney-client communications, and there is no guarantee that the foreign forum will protect the confidentiality at the level of the existing agreement.
http://www.ca2.uscourts.gov/decisions/isysquery/05194beb-c7ca-4533-89f8-3cdc4043f522/6/doc/17-424_opn.pdf#xml=http://www.ca2.uscourts.gov/decisions/isysquery/05194beb-c7ca-4533-89f8-3cdc4043f522/6/hilite/
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.