If it was just plain monetary concerns and sabotage of competitors I'd almost be fine with it, but it seems they actively want to monopolize most of human progress in their enlightened hands, lest the mob does something undesirable with these powers.

Fail cleanly. Anything else makes it too difficult to rely on.

edit: Giving the absolute maximum benefit of the doubt I understand that they see themselves as "stewards" for lack of a better word. But the EA thing is really leaking through, and paternalism isn't a good look.

Repro (de-identified): sample_dataset_group1.tsv - Geometry: Heatmap - X axis: frac_set set + condition (two columns → the "Add column" cross join) - Y axis: condition - Color: mean frac_set value, Sequential

When the X axis is a cross join of two columns (the second added via "Add column"), the x-axis tick labels (frac_set_2, frac_set_3, frac_set_4, frac_set_5) render in a broken state, rotated and offset, visually caught mid-transition, as if a CSS transition started and never settled to its resting position.

● Fable 5's safety measures flagged this message for cybersecurity or biology topics. They may flag safe, normal content as well. These measures let us bring you Mythos-level capability in other areas sooner, and we're working to refine them. Switched to Opus 4.8. Send feedback with /feedback or learn more

What's interesting is they say they'll change this to an explicit refusal in a few days, which seems too fast for them to retrain Fable/Mythos itself, so implies that this was always a filter in front of the model, and judging by how crude their "safety" filter is, this "might compete with us" filter is not going to be any better.

I also wonder who's paying for the tokens consumed by the filter (presumably also an LLM) - is that now factored into the input tokens cost? Hopefully(?) it is an LLM not just a regex like Claude Code's "sentiment" (swear) detector.

It's Anthropic's product and they can do what they want, but my concern is what happens if Fable's product team decides that they can route 25% of traffic to Opus, bill it as Fable, and max their KPIs. That just doesn't sit right.

Anthropic walks back policy that could have 'sabotaged' researchers using Claude - https://news.ycombinator.com/item?id=48485958 - June 2026 (30 comments)

Cybersecurity researchers aren't happy about the guardrails on Anthropic's Fable - https://news.ycombinator.com/item?id=48478969 - June 2026 (488 comments)

If Claude Fable stops helping you, you'll never know - https://news.ycombinator.com/item?id=48467896 - June 2026 (495 comments)

---

Also related, I guess?

AWS Bedrock to require sharing data with Anthropic for Mythos and future models - https://news.ycombinator.com/item?id=48473166 - June 2026 (248 comments)

Anthropic requires 30 day data retention for Fable and Mythos - https://news.ycombinator.com/item?id=48464258 - June 2026 (291 comments)

You can't blame the people commenting "they SAY they won't silently sabotage your session but how can we know?" because they're right, we can't ever know. And Anthropic has firmly planted the seeds of doubt.

They relied on trust that they were providing the service they were being paid for. That trust was blown, and an "oops, lets undo that" does not regain trust. It would be prudent to assume the invisible guardraild are possibly in play for all future Clause use, Fable or otherwise.

With the guard rails explicit or implicit do they refund back the tokens after you've hit the guard rails? I guess they don't. They could just throttle you just to save money then. You may be paying Fable prices but getting Haiku results with some excuse that well this coding issue sounds like a security bug.

I don't know, I'd rather have something less powerful but more predictable.

Seriously though, Fable was not that great facing a greenfield subject. It is excellent at oneshotting some math problems, but if you want it to do some cutting edge tech stuff, say like piecing together a new Crossplane XRD, by reading existing Helm chart and with application source code available. I still have to get a few pass for Fable to get it done right, and at this point I may consider making a skill for it. I even gave it the source code of the Crossplane itself and tell it to be careful about CRDs and data flow, but it is still pretty silly. Adaptiveness for Fable is still not great, and I think it is a well known problem for Anthropic, albeit all LLMs do suffer a lot from subjects they don't know and will hallucinate stuff very frequently.

I think it’s normal and morally fine for companies to want to protect their leadership position. I find the process of creating narratives that justify these decisions as something chosen for the good of others is a little tedious.

Maybe this is just a different set of people now realizing that Anthropic does this and has always done this?

Do not forget that this company is launching this thing at the moment it's trying to IPO. It's not rocket science that their very public steering/denial claim is really just them hinting to interested investors that their moat is absolute.

That decision keeps getting better and better as time goes on.

Does "SORRY" fix the deception these models use on the sly?

Does "SORRY" not silently downgrade you to a shittier model without notification?

Does "SORRY" refund your tokens or money?

Im guessing NO to all of those. Standard corporate sorry of "We're sorry youre offended and stupid and gullible".

also if they do this or not is unprovable and other labs will probably silently implement this too. it'll be 100% normal by this time next year

"You see, Mythos can automatically break out of a VM running on SELinux, but unfortunately this is too dangerous and we had to implement guardrails for the Fable peasants."

The beliefs of these people, and how they manifest, is deeply terrifying to me. They believe that any means are acceptable to achieve what they believe is a better end.

Neither OAI or Anthropic can be trusted.

But also, it isn’t the only huge mistake Anthropic has made in the last 48 hours. Having a sneaky data retention policy, while also giving companies no way to block Fable, is a massive problem. And it is ridiculous that Anthropic has so little respect for its customers. OpenAI should take advantage of this.

Why not just tell people, "To defend our ability to be competitive in our industry, we ask that you do not use Claude or any of our models to independently perform research on large language models or any of its related architectures or technologies. In order to prevent this violation of the Terms of Service, we have trained Claude Fable to deny any requests or prompts which involve frontier AI research."

They just showed that they CAN do this right in front of you. Local open weight models are a necessity.

I was a happy Max user.

God bless the Chinese companies releasing true open source models. Imagine a world without them, we would be at the mercy of unscrupulous people.