On Saturday, an unhappy customer vented online about an internet-connected garage-door opener he’d bought on Amazon. It was the sort of short, unremarkable comment that’s left thousands upon thousands of times a day by disgruntled shoppers who can’t get the gizmos they just brought home to work.

The device, Garadget, connects to existing garage-door hardware. It lets users remotely open and close their garage door from a smartphone, and alerts them whenever the garage is accessed.

“iPhone App will not stay open,” wrote Robert Martin (username: rdmart7) on Garadget’s official discussion board. “Wondering what kind of piece of shit I just purchased here…” For good measure, he hopped over to Garadget’s Amazon page, too, and left a one-star review there. “Junk - DO NOT WASTE YOUR MONEY.”

The routine complaint escalated quickly. That night, Martin heard back directly from the gadget’s creator, Denis Grisak—usually, this is the holy grail for a complaining customer—but Grisak was in no mood to help. He responded:

Martin,

The abusive language here and in your negative Amazon review, submitted minutes after experiencing a technical difficulty, only demonstrates your poor impulse control. I’m happy to provide the technical support to the customers on my Saturday night but I’m not going to tolerate any tantrums.

At this time your only option is return Garadget to Amazon for refund. Your unit ID 2f0036... will be denied server connection.

Without access to Garadget’s servers, the iPhone app can’t talk to the garage-door opener. So with that, Martin’s $99 purchase was rendered useless.

The back-and-forth between Martin and Grisak quickly ascended to the front page of Hacker News, a popular site that aggregates technology-related links. It even caught the attention of @internetofshit, a Twitter account dedicated to lambasting the silliest and least secure of internet-connected things.

The short saga of the garage opener lays bare the fundamentally odd nature of owning “smart” technology. As my colleagues Robinson Meyer and Alexis Madrigal wrote in 2014, when a device gets connected to the internet—whether it’s a cellphone, a thermostat, or a tea kettle—it’s no longer yours.

The future of networked devices will always depend, in part, on the intentions of their manufacturers. Will those connected lights regularly get software updates, or will they stop functioning when you get a new smartphone? Will the smart-home hub you bought last week get bought up by a competitor that will shut it down, turning the $300 gadget into a paperweight?

Now, add a new worry to the list: Will you anger the creator of the device you bought, pushing him to retaliate against you by bricking your gadget? To do so in ages past (like, say, 2002), Grisak would have had to sneak into Martin’s garage and bash in his garage-door opener with a baseball bat. Instead, he simply looked up the ID number of Martin’s device (2f0036) and blacklisted it from his server. That’s all it takes.

When I reached Grisak by email, he was somewhat contrite. “That was an overreaction on my part to a customer’s rude behavior in the community board,” he wrote. “The connection is now restored, though I doubt the customer will be interested in completing his installation.”

Martin indeed isn’t interested. He’s trying to return the gadget to Amazon, even though he bought it a few months ago. Grisak’s reaction to his complaint, he told me, was “a very unprofessional response that should do nothing but hurt his reputation and future business.”

Some commenters on Amazon and Hacker News wondered whether Grisak’s public online revenge was legal. One person encouraged Martin to reach out to his state attorney general’s office.

That’s a complicated question. Almost always, people who use a software program—from Microsoft Windows all the way down to a smartphone flashlight app—agree to a set of terms called an end-user license agreement. These agreements can include a clause that allows the software provider to cut off a user’s service at anytime. Most people reflexively click “agree” on these agreements without making even the smallest attempt to read them.

But Grisak told me that Garadget, which he described as a start-up, doesn’t have a license agreement. “Some legal stuff is still on the to-do list,” he wrote.

A bill signed into law signed in December prohibits companies from including “gag clauses” in the contracts they enter into with customers, meaning they can’t bring legal action against someone just for a negative review.

Although that law doesn’t directly address Grisak’s digital retaliation, it points to the types of customer protections that keep companies from intimidating consumers. “There’s a pretty strong public policy against preventing consumers from speaking about a product,” said Ira Rheingold, the executive director of the National Association of Consumer Advocates. She added that the act of retaliation could be challenged in court as an unfair practice under a state's consumer protection law and under common law.

Grisak says he’s committed to keeping Garadget alive for the long run. The software that runs on Garadget’s apps and devices is open source, so anybody can peruse the code, suggest improvements, and check for security issues. What’s more, the servers that keep the system functioning are prepaid “for years ahead,” he said. “I made a promise to customers and I’ll do everything in my power to ensure the service survives this episode. I deserved the beating; the customers did not.”

Customers who aren’t scared away from using the gizmo by its creator’s outburst might be relieved to hear that from Grisak. “What we really need from those building the Internet of Things is commitment,” wrote the anonymous proprietor of @internetofshit on The Verge last year. That’s particularly important for a project like Garadget, which was the product of a Kickstarter crowdfunding campaign. Although Kickstarter has produced a number of enduring, successful projects, many others crash and burn after raising many thousands of dollars.

But even without the issue of reliability, the Garadget episode is a reminder of how even an angry moment can turn a smart device into a dead one. After his complaint, Martin’s account on the Garadget discussion board was locked down, too. “This user is suspended until December 27, 2019,” his profile page read early Tuesday afternoon. “Reason: attitude.”

As an olive branch—or perhaps in an attempt to clean up the PR crisis he created—by Tuesday evening, Grisak had unfrozen Martin’s account.