For the first time in its 231-year history, the Supreme Court justices heard oral arguments remotely by phone and made the audio available live.
The new setup went off largely without difficulties, but produced some memorable moments, including one justice forgetting to unmute and an ill-timed bathroom break.
Here are the top five can't-miss moments from this week's history-making oral arguments.
A second week of arguments begin on Monday at 10 a.m. ET. Here's a rundown of the cases and how to listen.
1. Justice Clarence Thomas speaks ... a lot
Supreme Court oral arguments are verbal jousting matches. The justices pepper the lawyers with questions, interrupting counsel repeatedly and sometimes even interrupting each other.
Justice Clarence Thomas, who has sat on the bench for nearly 30 years, has made his dislike of the chaotic process well known, at one point not asking a question for a full decade.
But with no line of sight, the telephone arguments have to be rigidly organized, and each justice, in order of seniority, has an allotted 2 minutes for questioning.
It turn out that Thomas, second in seniority, may just have been waiting his turn. Rather than passing, as had been expected, he has been Mr. Chatty Cathy, using every one of his turns at bat so far.
Thomas broke a year-long silence on Monday in a trademark case testing whether a company can trademark by adding .com to a generic term. In this case, Booking.com.
"Could Booking acquire an 800 number, for example, that's a vanity number — 1-800-BOOKING, for example?" Thomas asked.
2. The unstoppable RBG
Justice Ruth Bader Ginsburg participated in Wednesday's argument from the hospital. In pain during Tuesday's arguments, the 87-year-old underwent non-surgical treatment for a gall bladder infection at Johns Hopkins Hospital later that day, according to a Supreme Court press release.
But she was ferocious on Wednesday morning, calling in from her hospital room in a case testing the Trump administration's new rule expanding exemptions from Obamacare's birth control mandate for nonprofits and some for-profit companies that have religious or moral objections to birth control.
"The glaring feature" of the Trump administration's new rules, is that they "toss to the winds entirely Congress' instruction that women need and shall have seamless, no-cost, comprehensive coverage," she said.
3. Who flushed?
During Wednesday's second oral argument, Barr v. American Association of Political Consultants, a case in which the justices weighed a First Amendment challenge to a federal rule than bans most robocalls, something very unexpected happened.
Partway through lawyer Roman Martinez's argument time, a toilet flush could be distinctly heard.
Martinez seemed unperturbed and continued speaking in spite of the awkward moment.
The flush quickly picked up steam online, becoming the first truly viral moment from the court's new livestream oral arguments.
4. Hello, where are you?
Justice Sonia Sotomayor, considered one of the most tech-savvy of the justices, experienced a couple of technical difficulties with her mute button.
In both Monday and Tuesday arguments, the first time she was at bat, there were prolonged pauses, prompting Chief Justice John Roberts to call, "Justice Sotomayor?" a few times before she hopped on with a brief, "Sorry, Chief," before launching into her questions.
By Wednesday she seemed to have gotten used to the new format, but the trouble then jumped to Thomas, who was entirely missing in action when his turn came. He ultimately went out of order Wednesday morning.
5. Running over time
Oral arguments usually run one hour almost exactly, with lawyers for each side having 30 minutes to make their case. In an attempt to stick as closely as possible to that format, the telephone rules allocate 2 minutes of questioning to each justice for each round of questioning.
Chief Justice John Roberts spent the week jumping into exchanges, cutting off both lawyers and justices in the process, to keep the proceedings on track. Even so the arguments ran longer than usual.
But in Wednesday's birth control case, oral arguments went a whopping 40 minutes longer than expected.
Justice Alito, for his part, hammered the lawyer challenging the Trump administration's new birth control rules for more than seven minutes, without interruption from the chief justice.
Referencing a decision he wrote in 2014, Alito said that "Hobby Lobby held that if a person sincerely believes that it is immoral to perform an act that has the effect of enabling another person to commit an immoral act, the federal court does not have the right to say that this person is wrong on the question of moral complicity. That is precisely the question here."
Christina Peck is NPR's legal affairs intern.