Weinberg learned basic programming on an Atari while he was still in elementary school. Before hitting puberty, he’d built an early internet bulletin board. “It didn’t really have a purpose” in the beginning, Weinberg says. The one feature that made his bulletin board unique, he says, was that he hosted anonymous AMA-style question panels with his father, an infectious disease doctor with substantial experience treating AIDS patients. This was during the early 1990s, when the stigma surrounding HIV and AIDS remained so great that doctors were known to deny treatment to those suffering from it. Weinberg says that the free—and private—medical advice made the board a valuable resource for the small number of people who found it. It was an early instance of Weinberg’s interest in facilitating access to information, as well as a cogent example of the power of online privacy: “The ability to access informational resources anonymously actually opens up that access significantly,” he told me over email.

After graduating from MIT in 2001, Weinberg launched a slew of businesses, none of which are particularly memorable. First there was an educational software program called Learnection. (“Terrible name… the idea was good, but 15 years too early,” he says.) Then he co-founded an early social networking company called Opobox, taking on no employees and writing all the code himself. “Facebook just kind of obliterated it,” Weinberg says, though he was able to sell the network to the parent company of Classmates.com for roughly $10 million in cash in 2006.

It was around that time when Weinberg began working on what would become DuckDuckGo. Google had yet to achieve total hegemony over the internet search field, and Weinberg felt that he could create a browser plugin that might help eliminate the scourge of spammy search results in other search engines.

Weinberg bought a billboard in San Francisco that proudly proclaimed, “Google tracks you. We don’t.” The stunt paid off in spades, doubling DuckDuckGo’s daily search traffic.

To build an algorithm that weeded out bad search results, he first had to do it by hand. “I took a large sample of different pages and hand-marked them as ‘spam’ or ‘not spam.’” The process of scraping the web, Weinberg says, inadvertently earned him a visit from the FBI. “Once they realized I was just crawling the web, they just went away,” he says. He also experimented with creating a proto-Quora service that allowed anyone to pose a question and have it answered by someone else, as well as a free alternative to Meetup.com. Eventually, he combined facets of all three efforts into a full-on search engine.

When Weinberg first launched DuckDuckGo in 2008 — the name is a wink to the children’s game of skipping over the wrong options to get to the right one — he differentiated his search engine by offering instant answers to basic questions (essentially an early open-source version of Google’s Answer Box), spam filtering, and highly customizable search results based on user preferences. “Those [were] things that early adopters kind of appreciated,” he says.

At the time, Weinberg says, consumer privacy was not a central concern. In 2009, when he made the decision to stop collecting personal search data, it was more a matter of practicality than a principled decision about civil liberties. Instead of storing troves of data on every user and targeting those users individually, DuckDuckGo would simply sell ads against search keywords. Most of DuckDuckGo’s revenue, he explains, is still generated this way. The system doesn’t capitalize on targeted ads, but, Weinberg says, “I think there’s a choice between squeezing out every ounce of profit and making ethical decisions that aren’t at the expense of society.”

Until 2011, Weinberg was DuckDuckGo’s sole full-time employee. That year, he pushed to expand the company. He bought a billboard in Google’s backyard of San Francisco that proudly proclaimed, “Google tracks you. We don’t.” (That defiant gesture and others like it were later parodied on HBO’s Silicon Valley.) The stunt paid off in spades, doubling DuckDuckGo’s daily search traffic. Weinberg began courting VC investors, eventually selling a minority stake in the company to Union Square Ventures, the firm that has also backed SoundCloud, Coinbase, Kickstarter, and Stripe. That fall, he hired his first full-time employee, and DuckDuckGo moved out of Weinberg’s house and into the strangest-looking office in all of Paoli, Pennsylvania.

Then, in 2013, digital privacy became front-page news. That year, NSA contractor Edward Snowden leaked a series of documents to the Guardian and the Washington Post revealing the existence of the NSA’s PRISM program, which granted the agency unfettered access to the personal data of millions of Americans through a secret back door into the servers of Google, Yahoo, Facebook, Apple, and other major internet firms. Though Google denied any knowledge of the program, the reputational damage had been done. DuckDuckGo rode a wave of press coverage, enjoying placement in stories that offered data privacy solutions to millions of newly freaked-out people worried that the government was spying on them.

“All of a sudden we were part of this international story,” Weinberg says. The next year, DuckDuckGo turned a profit. Shortly thereafter, Weinberg finally started paying himself a salary.