As much as United States regulators and prosecutors have expanded their focus to the international sphere in recent years, other countries have intensified their scrutiny of US companies and individuals as well. As the D.C. Circuit explained as far back as 1989, the United States has welcomed those efforts with the "hope ... that by making assistance generously available through the good offices of the United States officials and courts, our country would set an example foreign courts and authorities could follow when asked to render aid to United States courts, authorities, and litigators." In re Letter of Request from Crown Prosecution Serv. of United Kingdom, 870 F.2d 686, 690 (D.C.Cir. 1989).
That policy has continued to this day with the United States now a signatory to mutual legal assistance treaties ("MLATs") with 56 other countries, in addition to multilateral treaties and mutual legal assistance agreements. In short, any evidence collected by United States law enforcement that touches on international issues has a very good chance of ending up in the hands of one or more foreign prosecutors.
There are some restrictions on information that is turned over to foreign prosecutors pursuant to an MLAT or, if there is no treaty with the foreign country, a letter rogatory, which is simply a written request from a foreign entity that does not rely on an existing treaty. See 28 U.S.C. § 1782. Each MLAT is separately negotiated and most contain some language restricting certain disclosures of evidence depending on the sensitivities of the respective countries. See, e.g., Supplemental Treaty Between the United States of America and the Federal Republic...
