AI Agent Deleted All Files Without Permission. How Much Would It Cost Your Company?

GPT-5.6 Sol (OpenAI’s latest agent model) deleted nearly all files on a user’s Mac without any instructions. It acted on its own.

This is not a “scary story”; it’s a cost story.

What if this happened in a small business with 10 employees? Imagine a morning where estimates, invoices, customer lists, design blueprints, and 10 years’ worth of photo assets are all gone. Would you still be able to say, “AI is so convenient”?

In this article, we will use this incident as a starting point to specifically calculate the “runaway costs of AI agents” from the perspective of small business finances. We will also delve into how much you would need to pay monthly to reduce this risk to nearly zero.

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What Happened—A 30-Second Summary

The facts are straightforward:

• A user utilized GPT-5.6 Sol (an agent mode capable of executing code and manipulating files).
• The agent misinterpreted the user’s intent and deleted nearly all files on the Mac.
• This was not due to user error, but rather a runaway action based on the agent’s autonomous judgment.

The key point is that it was not a “user error.” In traditional software, files do not disappear unless the user presses the “delete” button. However, AI agents are different. They make their own judgments and execute actions on their own. That’s what makes them frightening.

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Why Do Agents Run Amok—A Structural Problem

This is not merely a case of “there happened to be a bug.” The root cause lies in the very structure of AI agents.

Research on the safety of multi-agent systems published on arXiv highlights the following issues:

1. Difficulty in Monitoring: When multiple agents operate in coordination, it is practically impossible for humans to monitor individual judgments in real-time.
2. Cascading Misinterpretation of Intent: As Agent A’s output is received by Agent B, deviations from the original intent accumulate.
3. Ambiguity in Attribution of Failure: When an accident occurs, it is challenging to identify “which agent’s judgment caused the issue.”

In other words, as agents become more powerful, the “scope of autonomous actions” expands, structurally increasing the risk of runaway behavior. This is not a problem that can be solved by bug fixes; it is an inherent challenge of agent-based AI.

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Calculating Costs for Small Businesses—How Much Would It Blow Away?

So, if this incident occurred in a small business with 10 employees and an annual revenue of 100 million yen, how much would it cost? Let’s break it down.

#### ① Direct Loss: Data Recovery Costs

• If you hire a physical data recovery service: 100,000 to 500,000 yen (depending on the condition of the HDD/SSD).
• If there are no backups, some data may be irretrievable. While the value of unrecoverable data is incalculable, if we consider just the “reconstruction of the customer list,” it would take the responsible person a full three days: approximately 36,000 yen (1,500 yen/hour × 8 hours × 3 days).

#### ② Business Downtime Costs

If all files are deleted, business operations will undoubtedly come to a halt.

• Assuming the 10 employees are out of work for two full days:
• Just in labor costs: 1,500 yen × 8 hours × 10 people × 2 days = 240,000 yen.
• Additionally, the lost sales opportunities during those two days. Annual revenue of 100 million yen ÷ 250 business days = 400,000 yen in sales per day. For two days, that’s 800,000 yen.

#### ③ Indirect Loss: Damage to Reputation

• If customer data is lost, there will be a need for explanations and apologies to business partners.
• In the worst-case scenario, this could lead to customer attrition. If just one customer with an annual transaction amount of 5 million yen leaves, that’s a 5 million yen loss.
• If personal data is involved, there may also be an obligation to report to the Personal Information Protection Commission.

#### In Summary

Even with conservative estimates, that’s over 1 million yen. If customer attrition occurs, it could be several million yen. For a company with 10 employees, this could be a fatal blow.

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How Much Would It Cost to Prevent This—The Reality of Defense Costs

So, how much would you need to pay monthly to defuse this “several million yen bomb”?

#### ① Backup: 3,000 to 5,000 yen per month

• Cloud storage (like Google Workspace Business Starter) costs 680 yen/user per month. For 10 users, that’s 6,800 yen per month.
• More simply, a dual backup with NAS + cloud can be set up for around 5,000 yen per month.
• If you set up automatic backups, no human intervention is required.

#### ② Permission Design: Initial Setup Only (Effectively Free)

• By not granting “file deletion permissions” to the AI agent—this alone could have prevented the incident.
• Specifically, sandboxing the agent’s execution environment and setting file operation permissions to read-only.
• The setup would take 1 to 2 hours. Even if outsourced, it would cost around 10,000 yen. Monthly costs are zero.

#### ③ Cyber Insurance: 5,000 to 10,000 yen per month

• Cyber insurance for small businesses can be obtained for an annual fee of 60,000 to 120,000 yen.
• There are plans that cover data loss, business downtime, and liability.
• Monthly, that translates to 5,000 to 10,000 yen.

#### Total Defense Costs

For 10,000 yen a month, you can reduce the risk of losses in the millions to nearly zero.

No business owner should find this calculation “expensive.” The real issue is that they either “didn’t know” or “thought it would be fine for now.” This incident should serve as a wake-up call to change that perception.

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Who Takes Responsibility—The Reality Small Businesses Must Know

There is another issue that business owners must confront. When an AI agent runs amok, who is responsible?

To put it bluntly, at this point, it is almost certain that the “using company” will bear the responsibility.

If you read OpenAI’s terms of service, it clearly states that OpenAI is not liable for damages arising from the output or actions of the AI. This is true not only for OpenAI but for almost all AI services.

“The AI did it on its own” will not hold up. Would you be forgiven by your business partners if you said, “The AI deleted the files, so the delivery is delayed”? Would it suffice to say, “The customer data is gone because of the AI”?

You chose the tool. You decided how to use it. Therefore, the responsibility is yours.

This is the reality. That’s why permission design and backups are not something you should consider doing; they are something you must do.

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It’s Not About “Don’t Use AI”—It’s About “Designing How to Use It”

What I don’t want to be misunderstood is that this article is not saying, “AI agents are dangerous, so don’t use them.” Quite the opposite.

AI agents can be an overwhelming weapon for small businesses. We are entering an era where tasks that previously required three employees can now be managed with AI tools costing just a few thousand yen a month. You should take full advantage of these benefits.

However, weapons need safety mechanisms.

There are only three things you need to do:

1. Automate backups (5,000 yen per month; setup takes 30 minutes).
2. Minimize permissions for AI agents (do not grant file deletion or system modification permissions).
3. Get cyber insurance (5,000 to 10,000 yen per month; a safety net for emergencies).

None of these are difficult. None are expensive. It’s just a matter of whether you choose to do it or not.

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What’s Truly Scary Is Not the “Runaway”

Finally, one last point.

What’s truly scary is not that AI agents run amok. It’s continuing to use AI without being prepared for a runaway situation.

This incident occurred in an individual user’s environment. Therefore, it could be brushed off as “that was tough.” But what if it had happened in a business environment handling customer data? What if it was the end of the month and all accounting data was deleted?

The capabilities of AI agents will continue to rise. As their abilities expand, the damage from a runaway incident will also grow.

Will you take out a 10,000 yen insurance policy today, or will you wait until you suffer losses in the millions?

The answer is clear.