Former spy-agency contractor Edward Snowden has caused a fierce debate over civil liberties and national security needs by disclosing details of secret U.S. government surveillance programs.
Reuters has uncovered previously unreported details about a separate program, run by the U.S. Drug Enforcement Administration, that extends well beyond intelligence gathering.
Its use, legal experts say, raises fundamental questions about whether the government is concealing information used to investigate and help build criminal cases against American citizens.
The DEA program is run by a secretive unit called the Special Operations Division, or SOD.
Here is how NSA efforts exposed by Snowden differ from the activities of the SOD.
Purpose of the programs
NSA: To use electronic surveillance to help the Federal Bureau of Investigation catchterrorists, the U.S. military fight wars, and the Central Intelligence Agency collectintelligence about foreign governments.
SOD: To help the DEA and other law enforcement agents launch criminal investigations of drugdealers, money launderers and other common criminals, including Americans. The unit also handlesglobal narco-terrorism cases.Gathering of evidence NSA: Much of what the agency does remains classified, but Snowden's recent disclosures showthat NSA not only eavesdrops on foreign communications but has also created a database ofvirtually every phone call made inside the United States.
SOD: The SOD forwards tips gleaned from NSA intercepts, wiretaps by foreign governments, court-approved domestic wiretaps and a database called DICE to federal agents and local lawenforcement officers.
The DICE database is different from the NSA phone-records database. DICE consists of about 1 billion records, and is primarily a compilation of phone log data that islegally gathered by the DEA through subpoenas or search warrants.
Disclosure to the accused
NSA: Collection of domestic data by the NSA and FBI for espionage and terrorism cases is regulated by the Foreign Intelligence Surveillance Act.
If prosecutors intend to use FISA orother classified evidence in court, they issue a public notice, and a judge determines whetherthe defense is entitled to review the evidence. In a court filing last week, prosecutors said they will now notify defendants whenever the NSA phone-records database is used during aninvestigation.
SOD: A document reviewed by Reuters shows that federal drug agents are trained to "recreate" the investigative trail to conceal the SOD's involvement. Defense attorneys, former prosecutorsand judges say the practice prevents defendants from even knowing about evidence that might beexculpatory.
They say it circumvents court procedures for weighing whether sensitive, classifiedor FISA evidence must be disclosed to a defendant.Oversight NSA: Congressional leaders and intelligence committee members are briefed on the NSA'sclassified programs.
The Foreign Intelligence Surveillance Court reviews and approves warrantsfor domestic eavesdropping.SOD: DEA officials who oversee the unit say the information sent to law enforcementauthorities was obtained through subpoena, court order and other legal means.
A DEA spokesmansaid members of Congress "have been briefed over the years about SOD programs and successes." This includes a 2011 letter to the Senate describing the DICE database. But the spokesman saidhe didn't know whether lawmakers have been briefed on how tips are being used in domestic criminal cases.