Among the most oft-repeated claims of the entire Russia election hacking scandal is that of absolute unanimity among US intelligence agencies, with media and politicians regularly claiming that "all 17 US intelligence agencies have agreed that Russia tried to influence the 2016 election to benefit Donald Trump." It's not true.
Nearly a year into the hacking scandal, both the New York Times and the Associated Press are finally copping to the fact that this allegation is untrue, and retracting it outright. The AP confirmed falsely making the claim in at least four distinct articles, most recently on Thursday.
What actually happened? The Director of National Intelligence made the allegation, claiming it was based on information from three US agencies, the CIA, FBI, and NSA. The Director of National Intelligence nominally represents all 17 intelligence agencies, and that was quickly and incorrectly extrapolated into all 17 agencies being in consensus.