In its latest user experiment, Facebook allegedly crashed its own app for Android users with the purpose of seeing how long it would take users to give up on using the social media site. The findings, intended to help Facebook develop a contingency plan should its relationship with Android operator Google ever go sour, were reportedly surprising: According to tech journal The Information, "the company wasn't able to reach the threshold" of when people would give up, because "people never stopped coming back." Even if the app was down for hours, The Guardian reports that users simply switched over from the app to the mobile version of the site.

Though this test reportedly happened just once "several years ago," The Guardian reports that the social network is catching flak for once again going too far in its user testing. As The Verge's Casey Newton explains, the real problem is that "users are almost totally unaware of these experiments." "And if they do eventually find out about them, they can't really leave — because there's simply no other meaningful Facebook-like service in the market," Newton writes. "That gives the company a moral imperative to treat its users honestly."

This isn't the first time Facebook experimented on its users, either. Back in 2014, Facebook found itself in hot water after it was revealed that it had experimented on users to study "emotional contagion" by purposefully putting more positive or negative content on news feeds to see if it affected what users then posted. Becca Stanek

President Trump's impeachment defense team is getting the celebrity treatment.

As Trump prepares for House impeachment managers to share their case against him on Tuesday, he has reportedly tapped some big-name lawyers with impeachment and televised trial experience to defend him. Former Special Counsel Ken Starr, his successor Robert Ray, and famous defense lawyer Alan Dershowitz are all expected to join Trump's legal team, sources have told The New York Times, CNN, The Wall Street Journal, and other publications.

White House Counsel Pat Cipollone and Trump's lawyer Jay Sekulow are slated to lead Trump's impeachment defense, the Times says. Dershowitz "will present oral arguments at the Senate trial," the legal team said in a statement, while Starr and Ray "are expected to play a constitutional and historic role," CNN reports. Former Florida Attorney General Pam Bondi and Trump's personal counsel Jane Raskin will reportedly also be on the team.

Both Starr and Ray are known for their work during former President Bill Clinton's impeachment, with Starr serving as the independent counsel whose report led to Clinton's impeachment, and Ray eventually replacing Starr and finishing up the reports in Clinton's case. Dershowitz was on defense team for O.J. Simpson and gained notoriety in that televised trial. His reported appointment fits with Trump's desire to turn his impeachment into a "TV spectacle." Dershowitz was also recently questioned over his ties to Jeffrey Epstein, who was accused of running a sex trafficking ring. Kathryn Krawczyk

Apparently Lara Trump didn't get the message about former Vice President Joe Biden's stutter.

Trump, who's married to President Trump's son Eric, decided to take a low blow at Biden during a Women for Trump event in Iowa on Thursday night. "I feel kind of sad for Joe Biden," she said, because "I'm supposed to want him to fail at every turn, but every time he comes on stage or they turn to him I'm like 'Joe can you get it out? Let's get the words out Joe.'"

Lara Trump probably should've heard by now that Biden worked to overcome the "debilitating stutter" he had as a child — a lesson former Press Secretary Sarah Huckabee Sanders learned when she mocked him for the same thing less than a month ago. Or perhaps she should've just followed first lady Melania Trump's "be best" advice and avoided sinking that low in the first place. Kathryn Krawczyk

Eleven Americans were injured in Iran's recent missile strike on the Al Asad Air base in Iraq, which President Trump and the Pentagon previously said resulted in no injuries.

The military confirmed Thursday that 11 Americans were treated for concussions after Iran last week struck two Iraqi bases housing U.S. troops, The New York Times reports. "While no U.S. servicemembers were killed in the Jan. 8 Iranian attack on Al Asad air base, several were treated for concussion symptoms from the blast and are still being assessed," a United States Central Command spokesperson told the Times.

Trump last week said "the American people should be extremely grateful and happy," as "no Americans were harmed" in the attack. The attack on the two bases came in response to a Trump-authorized U.S. drone strike that killed Iranian Gen. Qassem Soleimani.

CNN notes that "concussions are not always apparent immediately after they've been suffered," and a defense official told CNN that the Pentagon previously indicating that there were no injuries "was the commander's assessment at the time" but "symptoms emerged days after the fact, and they were treated out of an abundance of caution."

With this in mind, CNN's Jim Sciutto observed that "the crux" of the story "is not the Pentagon mislead," as "these injuries emerged only after the fact," but rather "that the Iranian missile strike was a nearer miss than advertised." Brendan Morrow

Guess who's back?

Eminem on Friday dropped the surprise album Music to be Murdered By, along with a music video for his song "Darkness" that advocates for gun reform while using imagery inspired by the Las Vegas shooting that left almost 60 people dead in 2017.

The disturbing video, which shows a gunman holed up in a Las Vegas hotel room and firing out the window, includes lyrics like "I'm a licensed owner with no prior convictions, so loss, the sky's the limit, so my supplies infinite."

The video ends with Eminem standing in front of a row of TV screens showing news reports of other mass shootings, pro-gun reform rallies, and President Trump, after which text on screen reads, "When will this end? When enough people care. Register to vote at Vote.gov. Make your voice heard and help change gun laws in America." The video also directs viewers to a website that highlights more information, including from the Giffords Law Center to Prevent Gun Violence.

The title of the surprise album, Eminem's first since 2018, is inspired by Alfred Hitchcock, and it even features audio of Hitchcock throughout. Of course, it wouldn't be an Eminem release if some of the lyrics hadn't already ignited controversy, and one stirring outrage makes reference to the Manchester Arena bombing that killed 22 people at an Ariana Grande concert. "I'm contemplating yelling 'bombs away' on the game like I'm outside of an Ariana Grande concert waiting," Eminem raps on "Unaccommodating."

Watch the "Darkness" video from Eminem below. Brendan Morrow

Iran's supreme leader, Ayatollah Ali Khamenei, led Friday prayers at a mosque in Tehran on Friday for the first time since 2012, trying to rally support among intertwined crises facing his government. On the foreign front, punishing U.S. sanctions have harmed Iran's economy and the Trump administration's killing of Iran's top general brought the U.S. and Tehran to the brink of war. Domestically, Iranians already angry over a hike in fuel prices took to the streets this week to demand justice and accountability for the Revolutionary Guard's downing of a Ukrainian jetliner, killing 176 people, most of them Iranian.

In nationally broadcast comments from inside the Mosalla mosque, Khamenei, 80, said the missiles fired on the Ukrainian jet were a "bitter accident" and defended the Revolutionary Guard, which reports directly to him. "Our enemies were as happy about the plane crash as we were sad," he said. "Happy that they had found something to question the Guard and the armed forces." He called President Trump, who has been encouraging the antigovernment protests, a "clown" who is only pretending to support Iran's people and would just as soon "push a poisonous dagger" into their backs.

Khamenei also addressed the missile strikes on two Iraqi bases hosting U.S. forces, calling the a "slap on the face" to the U.S. "The fact that Iran has the power to give such a slap to a world power shows the hand of God," he said, but pushing the U.S. military out of the Middle East would be the "real punishment" for America's "cowardly" killing of Gen. Qassem Soleimani, highlighting Soleimani's efficacy in battling the Islamic State. He added that the killing showed America's "terrorist nature."

"Leading Friday prayers in the capital is a symbolically significant act usually reserved for times when Iran's highest authority wishes to deliver an important message," BBC News reports, citing Mehdi Khalaji at the Washington Institute for Near East Policy. Peter Weber

"This afternoon, the Senate officially opened the impeachment trial of President Donald J. Trump," and "every single senator just swore to be an impartial juror," Stephen Colbert said on Thursday's Late Show. "For weeks, Republicans have been ignoring mounting evidence that Trump knew everything that was happening with the Ukraine scheme, and Democrats have been praying for the other shoe to drop. Well, last night, an entire Foot Locker fell out of the sky," thanks to Lev Parnas, a "recently indicted goon" who worked with Rudy Giuliani "to help Trump blackmail Ukraine into investigating Joe Biden."

Parnas "tossed Trump under Air Force One" in several "juicy" interviews, Colbert said, claiming Trump knew everything he and Giuliani were up to and never cared about corruption, just Ukraine announcing Biden investigations. "The only way this could be more damning for Trump is if there was some sort of phone transcript of him demanding investigation of — oh...." Colbert deadpanned. Trump refrained from tweeting about Parnas most of the day, "but this afternoon, the pressure finally got to him, and he blasted off this gem: 'I JUST GOT IMPEACHED FOR MAKING A PERFECT PHONE CALL!'"

Yes, "it was an all-caps kind of day for the president of the United States today," Jimmy Kimmel laughed at Kimmel Live. When the trial starts Tuesday, "senators will not be allowed to use their phones" and "they will have to stand when they cast votes — which is a big deal, because for a lot of these senators, this will be the first time they've ever stood for anything." Meanwhile, "the bombshells are still falling from the sky" as Parnas continues "to spill the borscht," Kimmel said, laying out some of the more damning revelations from Trump's "smoking goon. ... The whole scenario feels like The Sopranos, except instead of organized crime, it's disorganized."

"If those other people smelled the borscht, [Parnas] actually made it," and he's spooning out "some pretty big accusations," Trevor Noah said at The Daily Show. "And to make matters worse, a nonpartisan government agency declared that Trump withholding military aid from Ukraine was illegal. Yeah, the thing he actually did." And as Trump continues to claim he doesn't know Parnas, Parnas is responding "pics, it happened," he added. "You know the game is real when someone is threatening to open their camera roll."

Not that The Daily Show was waiting on Parnas. Peter Weber