The ACLU is taking the Justice Department to court to figure out when the government has to notify defendants that the government spied on them without a warrant. Somewhere within DOJ is a policy document titled “Determining Whether Evidence Is ‘Derived From’ Surveillance Under Title III or FISA.” Since much FISA surveillance occurs without a warrant, particularly that under its controversial Section 702, the document could shed light on when the government has to reveal potentially inadmissible acquisition of their email or Internet history.

But the government won’t give the ACLU the document, so the civil liberties group is suing for it. “Without definitive proof that the government spied on them, individuals have an incredibly difficult time challenging the government’s spying in court,” blogged the group’s Anna Diakun.

—Spencer Ackerman