The district courts of the United States and the United States courts of any Territory or other place subject to the jurisdiction of the United States shall have jurisdiction of violations of this subchapter or the rules, regulations, or orders thereunder, and, concurrently with State and Territorial courts, of all suits in equity and actions at law brought to enforce any liability or duty created by, or to enjoin any violation of, this subchapter or the rules, regulations, or orders thereunder. Any criminal proceeding may be brought in the district wherein any act or transaction constituting the violation occurred. A criminal proceeding based upon a violation of section 80a-33 of this title, or upon a failure to file a report or other document required to be filed under this subchapter, may be brought in the district wherein the defendant is an inhabitant or maintains his principal office or place of business. Any suit or action to enforce any liability or duty created by, or to enjoin any violation of, this subchapter or rules, regulations, or orders thereunder, may be brought in any such district or in the district wherein the defendant is an inhabitant or transacts business, and process in such cases may be served in any district of which the defendant is an inhabitant or transacts business or wherever the defendant may be found. In any action or proceeding instituted by the Commission under this subchapter in a United States district court for any judicial district, a subpoena issued to compel the attendance of a witness or the production of documents or tangible things (or both) at a hearing or trial may be served at any place within the United States. Rule 45(c)(3)(A)(ii) of the Federal Rules of Civil Procedure shall not apply to a subpoena issued under the preceding sentence. Judgments and decrees so rendered shall be subject to review as provided in sections 1254, 1291, 1292, and 1294 of title 28. No costs shall be assessed for or against the Commission in any proceeding under this subchapter brought by or against the Commission in any court. The Commission may intervene as a party in any action or suit to enforce any liability or duty created by, or to enjoin any noncompliance with, section 80a-35(b) of this title at any stage of such action or suit prior to final judgment therein.