In today’s letter: How to fix your broadband internet bill; hitting reset on kids’ screen time; cloud battle turns multi-front war; U.S. blames China for cyberattack; Saudi Arabia cashes in on EVs, and more. But first...

A group of Wall Street Journal reporters, editors, video producers and data scientists got together on one very cozy video call about six months ago to talk about an extremely pressing topic:

Power washer TikTok.

As in, the area of TikTok where you can watch video after video of people spraying high-pressure water at stuff. (Obviously, it rocks.)

It’s one of the many “rabbit holes” you can end up in on the rapidly growing social network.

But in this particular meeting we wondered: How does TikTok know to serve power washing to one viewer and french bulldogs to another? How does TikTok seem to figure out our unspoken interests and then serve more and more content about them to us?

The answer: one insanely powerful yet secretive algorithm.

To better understand it, we created over 100 automated TikTok accounts—or bots—that watched hundreds of thousands of videos on the app. We programmed each bot with specific interests but didn’t enter them into the app. The only way our accounts expressed their interests was by re-watching or pausing on videos with related hashtags or images.

What did we find? As you’ll see in our video, the TikTok experience starts the same way for everyone, with a variety of popular videos, many with millions of views. The app takes note of subtle cues, such as how long a user lingers on a video, to zero in on what they really want to watch. Over time, the videos TikTok serves can become less mainstream, less vetted by moderators and sometimes more disturbing.

Many of our accounts ended up deep in rabbit holes. The bot we featured in our video landed in one where TikTok showed it video after video about depression, with only a few examples of other types of content.

A TikTok spokeswoman said the simulated activity generated by this experiment isn’t representative of real user behavior because humans have a diverse set of interests. She also said that TikTok allows users to see less of something by selecting the “not interested” button.

Ultimately, we found that TikTok just needs you to watch videos to figure out your most hidden emotions or interests—whether they be about power washing or sexual power dynamics. For more on our findings and how TikTok’s algorithm works, watch the visual investigation here.

—Joanna, WSJ’s Senior Personal Technology Columnist, is based in New Jersey. Georgia is a WSJ tech reporter who covers TikTok, and is based in San Francisco.

Every year, blindsided by a broadband price hike as discounts expire, I wait on hold with my service provider to bring my monthly bill back down.

Our billing struggles are a symptom of a larger issue. Policy experts point to a lack of competition among broadband providers, which has led to higher prices, lower quality and unequal access. The Biden administration has proposed some fixes to increase broadband competition and promote fairer pricing, but in the meantime, if you think you’re paying too much, here are some tips from the pros.

👉 Read Nicole’s full column here.

Staying in Place: Apple is delaying its return to the office by at least a month as the Covid-19 Delta variant has led to a rise in infections and hospitalizations across the U.S. and world.

Pump Not Dump: Tesla CEO Elon Musk said that he and his rocket company, SpaceX, hold bitcoin, a cryptocurrency he generally supports despite having concerns about its environmental impacts.

Inventory Investment: Instacart plans to start building fulfillment centers for supermarkets over the next 12 months, in partnership with technology company Fabric, in or near grocery stores, with capacity for 10,000 to 50,000 items. The company will use robots to pull items from warehouses and have Instacart’s workers pack and deliver orders.

Camp drop-offs this summer have been particularly jarring for many children who spent the past year and a half glued to phones, tablets and game consoles. But as they return home—after weeks of in-real-life activities like canoeing, hiking and roasting s’mores, with no devices in sight—they should be in a better mind-set to accept new screen rules, child-development experts say.

👉 Read Julie’s full column here.

Many businesses have treated Amazon and Microsoft as the only options as they looked to embrace cloud-computing. But IT managers now are realizing they have leverage in an increasingly competitive industry.

👉 Read Aaron Tilley’s full report here.

• How China’s Hacking Entered a Reckless New Phase (Wired)

• Pegasus: The New Global Weapon for Silencing Journalists (Forbidden Stories)

• Mark in the Metaverse (The Verge)

Hackers working for the Chinese government compromised more than a dozen U.S. pipeline operators nearly a decade ago, the Biden administration revealed Tuesday while also issuing first-of-its-kind cybersecurity requirements on the pipeline industry.

👉 Read Dustin Volz’s full report here.

Amazon founder Jeff Bezos and three other passengers successfully crossed the Karman Line, an imaginary boundary considered by many the beginning of space, a few miles higher than Richard Branson’s recent Virgin Galactic flight.

🎬 More on the Amazon founder:

From Bookseller to Blue Origin—A Look Back at the Career of Jeff Bezos

The single biggest financial beneficiary of the recent U.S. electric-vehicle startup boom is an unlikely candidate: the world’s largest exporter of oil.

The kingdom of Saudi Arabia stands to record a profit of nearly $20 billion on a $2.9 billion investment in Lucid Motors, a San Francisco Bay Area electric-car maker.

👉 Read Eliot Brown’s full report here.

...when Peppa Pig syndrome is infecting our youngest.

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Brought to you by tech editor Robert Wall, tech news editor Bowdeya Tweh and Personal Tech bureau chief Wilson Rothman. You can reach them by replying to this newsletter, and follow them on Twitter: @R_Wall, @bowknowsbiz and @wjrothman.