1) Incidental collection: When your name gets caught up in surveillance that's not about you. It's not unusual for the communications of American citizens to be incidentally collected if they talk to a foreigner who is under surveillance.
Why it's in the news: It's key to understanding Trump's wiretapping allegations and how he has been trying to walk back from it. There is no evidence to prove the president's claim that then-President Barack Obama tapped his phones during the campaign. But House Intelligence Committee Chairman Devin Nunes (R-Calif.) did trek up to the White House in late March to tell the president he found evidence that Trump and his associates may have been caught up in incidental collection unrelated to Russia.
That led Nunes to temporarily step down from his committee's Russia investigation over concerns that he compromised the investigation — Trump and his associates may be part of it, after all.
2) Unmasked: When the identity of a U.S. citizen caught up in surveillance is revealed, either publicly or among intelligence agencies. Only about 20 people in the whole security apparatus know the person's true identity when they're not unmasked. National Security Agency chief Mike Rogers testified to Congress in March that a U.S. citizen's identity is unmasked only if that person is directly related to the context of the intelligence.
Why it's in the news: Some days it seems as though everyone in Washington is accusing everyone of unmasking everyone.
Most recently, Obama's former national security adviser, Susan E. Rice, seemed to say she wasn't aware that Trump and his team were caught up in incidental collection that Nunes shared. And then it was reported that she had asked to have some of the identities of Trump associates unmasked. (There is zero evidence she used this information for anything other than her official duties, but Republicans seized on the discrepancy as a potential example of the Obama administration using intelligence for political purposes.)
3) Leaks: When something gets made public that an institution didn't want to be public.
Why it's in the news: The Trump administration is desperately trying to plug many leaks to the media. Because of leaks, we know about Flynn's conversations with the Russian ambassador to the United States that eventually led to his firing, Attorney General Jeff Sessions's conversations with the Russian ambassador that eventually led to his recusal from all Justice Department investigations of Trump and Russia, top Trump adviser Jared Kushner's conversations with Russian officials and our next item, below.
4) FISA warrant: An okay from a secret intelligence court to monitor an American citizen. FBI Director James B. Comey has said applications to get a FISA warrant are thicker than his wrists, and requesting one must be approved at the highest levels of the Department of Justice and the FBI and then authorized by a secret court.
Why it's in the news: The Washington Post reported earlier in April that the FBI asked for — and received — a FISA warrant to monitor Trump's former foreign policy adviser Carter Page's communications. The warrant suggested there was probable cause that Page may have been acting as an agent of Russia.
FISA warrants are one of the United States' most closely guarded secrets, so this was a major leak from the intelligence community to the media. Page has not been accused of any crime and denied this accusation.
5) SCIF: A spy-proof room. It stands for a “sensitive compartmented information facility,” and it's a room that allows American officials to share and discuss classified information without worrying about that info being hacked or their conversations secretly recorded. There are SCIFs in Congress, at the White House, at the FBI and the CIA, and at other national security facilities and embassies all over the world.
Why it's in the news: Lawmakers are confused as to why Trump invited all 100 senators to the White House on Wednesday for a classified briefing about North Korea. The White House will temporarily turn an auditorium in its building next door into a SCIF despite the fact that there is a secret room big enough for all of them on Capitol Hill. “These briefings are always, always, always done in the SCIF up here,” one puzzled Senate aide told The Post's David Nakamura and Ed O'Keefe.
6) Classified information: Information that the government deems would be harmful to national security if it were made public. There are different levels of classified information: confidential, secret, top secret. The president issues general guidelines to federal agencies about what information to classify. When the FBI said Hillary Clinton was “extremely careless” with classified information she shared on a private email server, she responded that she thought some classification levels were too stringent.
Why it's in the news: Pretty much any spy story you read in the news will deal with some level of classified information. It could be officials refusing to share information because it's classified (we don't know much about the FBI's investigation of Trump ties to Russia, and the Senate and House intelligence committees are doing much of their work behind closed doors for that reason). Conversely, any major leak you read is likely to involve some level of classified information made public.
7) The National Security Council: It's exactly what it sounds like: an advisory council to the president on issues of national security.
Why it's in the news: Each president has shaped the council's influence as he sees fit, but Trump came under criticism for putting an overtly political person on the team while downgrading the role of nonpolitical intelligence and military officials. The Trump administration recently announced that its top political aide, Stephen K. Bannon, is off the council.