Update 5:00 pm PST: The FBI applied for FISA (Foreign Intelligence Surveillance Act) warrants to monitor four members of the Trump team suspected of contacts with the Russian government. The Guardian reported:

The Guardian has learned that the FBI applied for a warrant from the foreign intelligence surveillance (Fisa) court over the summer in order to monitor four members of the Trump team suspected of irregular contacts with Russian officials. The Fisa court turned down the application asking FBI counter-intelligence investigators to narrow its focus. According to one report, the FBI was finally granted a warrant in October, but that has not been confirmed, and it is not clear whether any warrant led to a full investigation.

Update 4:45 pm PST: Sen. John McCain (R-AZ), the chairman of the Senate Armed Services Committee, "passed documents to the FBI director, James Comey, last month alleging secret contacts between the Trump campaign and Moscow and that Russian intelligence had personally compromising material on the president-elect himself," reported The Guardian late Tuesday. "McCain is not thought to have made a judgment on the reliability of the documents but was sufficiently impressed by the source’s credentials to feel obliged to pass them to the FBI."

The most shocking element of the report alleges that "FSB [Russian intelligence] has compromised Trump through his activities in Moscow sufficiently to be able to blackmail him."

Original:

The country’s top intelligence officials presented classified documents to both the White House and the President-elect revealing that Russian operatives claim to have compromised Donald Trump’s personal and financial information, CNN reported Tuesday. The information has not yet been verified; as Buzzfeed reported:

A dossier making explosive — but unverified — allegations that the Russian government has been “cultivating, supporting and assisting” President-elect Donald Trump for years and gained compromising information about him has been circulating among elected officials, intelligence agents, and journalists for weeks.

The dossier, which is a collection of memos written over a period of months, includes specific, unverified, and potentially unverifiable allegations of contact between Trump aides and Russian operatives, and graphic claims of sexual acts documented by the Russians.

Buzzfeed added:

It is not just unconfirmed: It includes some clear errors. The report misspells the name of one company, “Alpha Group,” throughout. It is Alfa Group. The report says the settlement of Barvikha, outside Moscow, is “reserved for the residences of the top leadership and their close associates.” It is not reserved for anyone, and it is also populated by the very wealthy.

CNN spoke to U.S. officials with direct knowledge of the intelligence briefings who explained that Western foreign espionage agencies first learned that Trump may have been compromised during the 2016 election. The nature of the privacy breach hasn’t been disclosed to the public. It’s unclear how much and what kind of information Russian spies are sitting on. As Friday’s intelligence community report on Russian hacking activities explicitly noted, U.S. intelligence services rarely, if ever, reveal “sources and methods.” Such a disclosure would impair future intelligence-gathering efforts.

But here’s what we know so far:

“The allegations were presented in a two-page synopsis that was appended to a report on Russian interference in the 2016 election,” reported CNN, adding:

The allegations came, in part, from memos compiled by a former British intelligence operative, whose past work US intelligence officials consider credible. The FBI is investigating the credibility and accuracy of these allegations, which are based primarily on information from Russian sources, but has not confirmed many essential details in the memos about Mr. Trump.

The information was presented to Trump at his building in Manhattan by the nation’s foremost intelligence officials, including Director of National Intelligence James Clapper, FBI Director James Comey, CIA Director John Brennan, and NSA Director Admiral Mike Rogers.

The president-elect was also briefed on the Russia’s influence campaign during the 2016 presidential election.

As Friday’s IC report detailed, Kremlin-backed hackers gathered information about both political parties, but only the purloined emails of Democratic candidate Hillary Clinton and the DNC were given to WikiLeaks to ultimately unveil in an attempt to undermine Clinton’s public image. All 17 US intelligence agencies believe that Moscow not only preferred Republican candidate Donald Trump over Clinton, but engaged in a coordinated campaign involving covert (hacking emails) and overt operations (propaganda via its propaganda news site RT) to sway the election for Trump. Russian president Vladimir Putin’s personal animus against Clinton factored largely into this calculation. Clinton’s aggressive policies against Russia, including her call for safe-zones in Syria, likely exacerbated Putin’s aversion to a Clinton presidency.

Notably, Trump affiliates may have also been in direct contact with the Russian government, asserted the intel chiefs.

CNN explained: “The two-page synopsis also included allegations that there was a continuing exchange of information during the campaign between Trump surrogates and intermediaries for the Russian government, according to two national security officials.”

Team Trump has long been accused of being far too cozy with the Russians. Former campaign manager Paul Manafort, national security adviser Lt. Gen. Michael Flynn, and Secretary of State nominee Rex Tillerson have all been implicated in these accusations: Manafort reportedly spearheaded a propaganda campaign for Kremlin ally and former Ukrainian President Victor Yanukovych before the Russian puppet was ousted from office by a people’s uprising in Maiden Square, Kiev; Flynn has made frequent appearances on Russian propaganda channel RT (formerly known as Russia Today), assuming Russophilic positions when it came to the invasion of Crimea and Syria.

Flynn sat alongside Putin at a Kremlin banquet held in Moscow. The suspicious circumstances surrounding Flynn’s abrupt exit from his post as Director of National Intelligence under the Obama administration is still a topic of conversation among national security and intelligence analysts; Tillerson forged a multi-millionaire dollar oil deal with Russia in his capacity as CEO of ExxonMobil. He has a personal, friendly relationship with President Putin.