10 things you need to know today: October 22, 2016

Republican Donald Trump will give a major speech in historic Gettysburg, Pennsylvania, Saturday morning to lay out his plans for his first 100 days in office if elected president. An advance copy of the speech was not released, but campaign staff said it would be a "very specific, detailed vision" for "economic and physical security." One Trump aide compared the speech to the 1994 GOP "Contract with America," and another said rival Hillary Clinton could not make a similar presentation because she "doesn't have a governing vision for America because she has no vision." Also on Saturday, the 11th woman to accuse Trump of sexual misconduct is expected to come forward.

WikiLeaks said its supporters are responsible for the massive cyberattack Friday which took down numerous major websites, including The New York Times, Twitter, Etsy, Tumblr, and more. "Mr. Assange is still alive and WikiLeaks is still publishing," the organization wrote in a tweet Friday afternoon. "We ask supporters to stop taking down the US internet. You proved your point." Hacktivist groups Anonymous and New World confirmed the tweet's implications, saying they orchestrated the attack as retaliation for the Ecuadorian government's decision to take away internet access from WikiLeaks founder Julian Assange following his site's ongoing release of emails hacked from the Hillary Clinton campaign. The attack took affected pages down for at least two hours Friday morning and sporadically throughout the afternoon. The outages appear to stem from a massive distributed denial of service (DDoS) attack against Dyn, an internet provider company based in New Hampshire.

Democrat Hillary Clinton's campaign headquarters were partially evacuated Friday night after a mailed envelope containing a mysterious white powder was discovered. New York City law enforcement investigated the substance and determined it was not hazardous, though its exact nature has not been released. None of the four campaign staffers who had contact with the powder have reported any symptoms of illness. Shortly after the 9/11 attacks in 2001, similar envelopes of white powder mailed to multiple locations around the United States were found to contain spores of anthrax, a potentially deadly bacteria.

Islamic State militants rounded up and murdered 284 men and boys on Thursday and Friday in Mosul, Iraq, an intelligence source told CNN, as Iraqi and American forces continue to make their approach to retake the town. Mosul is the last major city ISIS controls in Iraq, and those killed in this mass slaughter were previously used as human shields by ISIS terrorists attempting to retain territory in the area. CNN's source says all the victims were shot and buried in a mass grave at a former university.

U.S. Secretary of Defense Ash Carter made an unannounced visit to Iraq Saturday to monitor progress in the joint U.S.-Iraqi attempt to recapture Mosul from the Islamic State. Carter's visit marked the sixth day of the Mosul campaign and coincided with Iraqi forces successfully reclaiming a village outside Mosul that is predominantly populated by Iraq's persecuted Christian minority. The village was under ISIS control since 2014. Carter will meet with Iraqi officials during his trip and assess the situation in Mosul.

Donald Trump's posts on Facebook were flagged by users as hate speech, employees told The Wall Street Journal in an article published Friday, and some Facebook employees wanted the Republican candidate's posts pulled from the site. CEO Mark Zuckerberg ultimately ruled against their removal, saying it would send the wrong message to censor a presidential candidate. Also on Friday, the social networking giant announced it would loosen censorship rules when the content in question is adequately newsworthy. "In the weeks ahead, we're going to begin allowing more items that people find newsworthy, significant, or important to the public interest," said a statement from two Facebook vice presidents, "even if they might otherwise violate our standards" for graphic or offensive content.

While campaigning Friday in Fletcher, North Carolina, Donald Trump justified his attacks on Hillary Clinton's handling of her husband's infidelities by claiming first lady Michelle Obama leveled them first. "Wasn't [Obama] the one that originally started the statement, if you can't take care of your home ... you can't take care of the White House or the country?" Trump asked — but he failed to note that the full context of Obama's 2007 remarks indicates she was talking about balancing childcare with presidential obligations.

The two Minneapolis, Minnesota, police officers responsible for the fatal shooting of Jamar Clark followed proper procedure and will not face disciplinary action, the Minneapolis police department chief said Friday. An internal investigation ruled the officers were in the right when they used deadly force against the 24-year-old black man this past November. The circumstances of Clark's death were much debated and the subject of Black Lives Matter protests last fall. The officers were attempting to arrest Clark for interfering with paramedics' treatment of a woman, at which point one of the cops says Clark attempted to take and use his gun, provoking the officers' escalation as a means of self defense.

Bridget Anne Kelly, the former aide to New Jersey Gov. Chris Christie (R) who sent the infamous "time for some traffic problems in Fort Lee" email at the center of Christie's Bridgegate scandal, took the stand Friday in the federal trial surrounding the 2013 incident. In her testimony, Kelly claimed the proposal to close access lanes to the bridge was presented to her as a "traffic study." The governor's staff is accused of closing the lanes as political retaliation against Fort Lee Mayor Mark Sokolich (D), who declined to endorse Christie in his re-election race. Kelly is on trial with Bill Baroni, another former Port Authority official, and each faces conspiracy and fraud charges.

New York Gov. Andrew Cuomo on Friday signed a law authorizing tough new restrictions on Airbnb, the popular peer-to-peer rental service. Advocates of the measure say Airbnb hurts the hotel industry and reduces affordable housing stock in places like New York City. Opponents argue hotels have wrangled special state protection from fair market competition, and New Yorkers should be allowed to rent their homes as they please. The bill comes with fines up to $7,500, though it will be difficult to enforce. Short-term rentals will still be permitted if the resident is present, meaning Airbnb listings can offer a room but not an entire house or apartment.