Marissa (Mayer, Yahoo CEO) walked me through exactly what that would look like, what that could look like, and she showed me an opportunity for Tumblr to stay an independent company, effort and team. Now, we can keep pursuing this mission and vision for our product with all this new wind behind our sails.

… It’s true that we don’t have the same demographic information that a Facebook does and we likely won’t. But we have one of the most robust networks of content and the most highly engaged audience of humans that comes there hungry for that content. What that means is, creative advertisers who make great ads that blend in with that content have the opportunity to tell a story that resonates with people in an incredibly human way that no level of targeting is going to be able to replicate.

The board of Yahoo, the faded Web pioneer, agreed on Sunday to buy the popular blogging service Tumblr for about $1.1 billion in cash, people with direct knowledge of the matter said, a signal of how the company plans to reposition itself as the technology industry makes a headlong rush into social media.

The deal, which is expected to be announced as soon as Monday, would be the largest acquisition of a social networking company in years, surpassing Facebook’s $1 billion purchase of Instagram last year.

For Yahoo and its chief executive, Marissa Mayer, buying Tumblr would be a bold move as she tries to breathe new life into the company. The deal, the seventh since Ms. Mayer defected from Google last summer to take over the company, would be her biggest yet. It is meant to give her company more appeal to young people, and to make up for years of missing out on the revolutions in social networking and mobile devices. Tumblr has over 108 million blogs, with many highly active users.

Yet even with all those users, a basic question about Tumblr and other social media sites remains open: Can they make money?

Founded six years ago, Tumblr has attracted a loyal following and raised millions from big-name investors. Still, it has not proved that it can be profitable, nor that it can succeed on mobile devices, which are becoming the gateway to the Internet. Even Facebook faces continued pressure from investors to show it can increase its profits and adapt to the mobile world.

“The challenge has always been, how do you monetize eyeballs?” said Charlene Li, the founder of the Altimeter Group, a consulting firm. “Services like Instagram and Facebook always focus on the user experience first. Once that loyalty is there, they figure out how to carefully, ideally, make money on it.”

A Yahoo spokeswoman declined to comment. A representative for Tumblr did not respond to requests for comment.

If the deal is approved, Ms. Mayer will face the challenge of successfully managing the takeover, given Yahoo’s notorious reputation for paying big money for start-ups and then letting the prizes wither. Previous acquisitions by Yahoo, like the purchase of Flickr for $35 million and a $3.6 billion deal for GeoCities, an early pioneer in social networking, have been either shut down or neglected within the company.

Because of this, Ms. Mayer will face pressure to keep Tumblr’s staff, led by its founder, the 26-year-old David Karp, who dropped out of high school as a 15-year-old programmer. It is unclear whether all of Tumblr’s 175 employees, based in New York City, will move over to Yahoo.

George Gascón, San Francisco’s district attorney, says handset makers like Apple should be exploring new technologies that could help prevent theft. In March, he said, he met with an Apple executive, Michael Foulkes, who handles its government relations, to discuss how the company could improve its antitheft technology. But he left the meeting, he said, with no promise that Apple was working to do so.

He added, “Unlike other types of crimes, this is a crime that could be easily fixed with a technological solution.”

Apple declined to comment.

The cellphone market is hugely lucrative, with the sale of handsets bringing in $69 billion in the United States last year, according to IDC, the research firm. Yet, thefts of smartphones keep increasing, and victims keep replacing them.

In San Francisco last year, nearly half of all robberies involved a cellphone, up from 36 percent the year before; in Washington, cellphones were taken in 42 percent of robberies, a record. In New York, theft of iPhones and iPads last year accounted for 14 percent of all crimes.

Some compare the epidemic of phone theft to car theft, which was a rampant problem more than a decade ago until auto manufacturers improved antitheft technology.

“If you look at auto theft, it has really plummeted in this country because technology has advanced so much and the manufacturers recognize the importance of it,” said Chuck Wexler, the executive director of the Police Executive Research Forum, a nonprofit group focused on improving police techniques. “The cellphone industry has for the most part been in denial. For whatever reasons, it has been slow to move.”

This is a major breakthrough in computing. We now have machines that can receive bad news and flip their shit millions of times faster than any human being!

Joel, this is Marty. I’m calling you from a cell phone. A real handheld portable cell phone.

A federal appeals court in New York on Monday upheld a ruling in favor of Aereo, the start-up Internet service that streams stations without compensating them. The decision set the stage for a full-blown trial.

The broadcasters, surprised and disappointed, said they were confident they would prevail eventually. But as the legal battles continue, Aereo, for now available only in New York City, plans to offer its service in nearly two dozen more cities this year.

The service’s triumphant backer, the media mogul Barry Diller, said of the ruling: “We always thought our Aereo platform was permissible and I’m glad the court has denied the injunction. Now we’ll build out the rest of the U.S.”

Aereo is able to stream broadcast stations by operating an array of tiny antennas that pick up over-the-air signals. Subscribers paying about $8 a month receive control over one antenna and can select programming over the Internet. Aereo essentially turns the subscriber’s phone, computer or tablet into a small television set, but without the rabbit ears that would normally be needed.

The array of antennas in Brooklyn allows Aereo to avoid paying the retransmission fees that operators like Time Warner Cable and DirecTV pay for access to stations. Those fees are an increasingly important revenue source for the stations, so it is not surprising their owners have sued to protect them.

The broadcasters, including CBS Corporation, Comcast, News Corporation and the Walt Disney Company, filed two suits against Aereo more than a year ago, weeks before the service was made available in New York. But a district court judge denied the request for a preliminary injunction last summer.

The Court of Appeals for the Second Circuit affirmed the lower court ruling on Monday in a 2-to-1 decision, saying that Aereo’s streams of TV shows to individual subscribers did not constitute “public performances,” and thus the broadcasters’ copyright infringement lawsuits against the service “are not likely to prevail on the merits.”