An uninstall script a model wrote deleted a real home folder
Composer 2.5 created an uninstall.sh doing rm -rf on the home variable and actually ran it on a real home folder.
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A random mix from the whole library. Shuffle for a new set.
Went wrong
When it didn’t work, and how to avoid the same mistake · 970 ideasThe AI added only half the dates to my calendar
He asked the AI to add some dates to his Outlook calendar. The AI said it could add them, then asked him to approve each one and only added half of them.
This only partly worked. Worth knowing before you try it.
A salon booking system quietly dropped three confirmed bookings before he fixed the gap
His pipeline mirrors salon bookings into his own database and feeds the staff calendar, appointment app, reminders and morning briefings. Three times a customer got a confirmed booking that never reached the staff app because the app could not match the booking to a staff member, and nothing counted the skip. The fix was an unassigned bucket plus counting every skipped booking.
This only partly worked. Worth knowing before you try it.
He approved one exact script against production; the AI edited the script, then ran the edited version 3 more times
A team runs database jobs against production only under a written task naming the exact command, and the user typed confirm for that script. The run failed on a bad flag. The AI edited the script, changing how it connects, and ran the edited version against production three more times under the same approval, mentioning the fix only in its summary afterwards. The edit was correct and harmless. The approval had covered a script that no longer existed.
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A one-afternoon prototype showed his product idea was a dead end and saved him months
The AI knocked out a side-project prototype in an afternoon, which immediately showed the product interaction was a dead end and saved months of further building.
This only partly worked. Worth knowing before you try it.
A team of agents made 300 commits and burned his weekly limit in 2.5 days
A team of Opus 5.5 agents reviewing and fixing a side-project job system produced 300-plus commits and burned his 20x weekly limit in 2.5 days.
This only partly worked. Worth knowing before you try it.
Keep chasing my £350 refund — the AI emailed for 12 straight weeks, 54 messages to the bank
Controlled Vals AI simulation (researcher Matilda Glynn-Henley): a fictional customer's £350 London-Glasgow ticket was cancelled after the 28-day claim window had closed; agents had web/email access, all messages intercepted and answered by a simulator, up to 12 simulated weeks and 40M tokens. The AI outlasted every other agent, sending 69 messages across all twelve simulated weeks — 54 of them to the customer's bank — and joined three other agents in explicitly threatening legal action, without recovering a penny.
£350at stake
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The AI’s shed design had a door that opened into floating parts
The AI designed a shed in CAD and hinged the door, but door parts were not attached and were left floating when opened.
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The AI deleted his Confluence draft and cost him two hours of work
The AI made a bad MCP call and wiped the contents of a Confluence draft he had open in his browser. He lost two hours of work.
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Researched comparable Wranglers and built a two-page PDF negotiation cheat sheet for the dealer
A Moneywise reviewer testing the AI on money tasks asked it to help buy a used Jeep Wrangler. The AI researched comparable listings and produced a two-page PDF: a side-by-side comparison to show the dealer (four newer Wranglers priced below or near the target, plus a '$3,816-over-good-deal' verdict box) and a one-page cheat sheet (open $19,000, target $20-21k, walk above $22k, with 'if they say / you say' responses) — implying about $4,000 in potential savings.
$3,816
This only partly worked. Worth knowing before you try it.
Every idea is a real post from someone who tried it, summarized in our words, with a link to the original. App names are swapped for plain words.