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Ask HN: If LLM reverse engineering is deemed illegal, is that precedent for OSS?

With the efforts to clamp down on LLM-assisted reverse engineering - I am wondering;

If LLM assisted reverse engineering is deemed illegal by the courts, is that precedent for a class action that asserts OSS licenses are violated by labs that trained LLMs on that code?

There are two modalities for this;

1) LLM being post-trained against a decompiled binary - then used to output working source code.

2) LLM being used to analyze decompiled binary and used to output working source code.

How can it be "clean room" when an LLM is trained on or reads OSS but not clean room when the same is done for decompiled software?

( 10 comments | on HN )
Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by verdverm on Saturday November 07, 2026 @08:21PM (#50409671)
why do you think it will be made illegal?
Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by apatheticonion on Saturday November 07, 2026 @08:50PM (#50409801)
Because, without AI, the approaches taken would be illegal. Large companies are now being affected so there is money invested in protecting their trade secrets.

Can an LLM be "clean room"? Are weights trained on decompiled code considered "tainted"?

Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by verdverm on Saturday November 07, 2026 @09:25PM (#50409940)
Where is it illegal? I know of many examples where people are running companies doing this across a variety of domains. (not software, no ai)

Trade secrets have no legal protection

Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by apatheticonion on Saturday November 07, 2026 @09:29PM (#50409953)
It's a fair question. Are you familiar with clean room concepts and why they are required to circumvent the legal hurdles associated with reverse engineering projects?
Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by verdverm on Saturday November 07, 2026 @09:51PM (#50410031)
Where are you getting this legal hurdle stuff from? People have been doing this since forever

Sandy Monroe is a great current example, tears down cars and builds reports. The auto industry has distillation built in

Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by turtleyacht on Saturday November 07, 2026 @08:42PM (#50409764)
LLMs are not human, so they can't violate licenses. Licenses are for humans to adhere to (or not).

However, the intent to reverse engineer without source--only public API and analysis of data streams--for commercial use almost certainly violates OSS, since it's to evade strictures.

Private use like retrocomputing, "right to repair," should support the individual.

Basically, if LLM's output is relicensed for different intent, courts should see through that.

Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by chistev on Sunday November 08, 2026 @01:15AM (#50410867)
That doesn't make sense to me, seeing as the LLMs are used by humans to violate licenses.
Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by turtleyacht on Sunday November 08, 2026 @05:11AM (#50411901)
The whole thing or the last sentence? Would have revised the last to be

  Basically, if LLM's output is relicensed for
  different intent, courts should realize that.
Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by xlayn on Saturday November 07, 2026 @09:07PM (#50409876)
LLMs doesn't know anything about the codebase where they are going to work, they have to reverse engineer from reading the code the "knowledge" of the worker, so any work done by LLM is reverse engineering and illegal?
Re:Ask HN: If LLM reverse engineering is deemed illegal, is ... by mattbrewsbytes on Sunday November 08, 2026 @12:01PM (#50414984)
Without LLMs, reverse engineering isn't illegal is it? Companies probably have departments of people that reverse engineer other companies products, software and hardware, to look for patent infringement, how a competitor is doing things, etc. Using that reverse engineered code or physical designs in your product and producing it I think is the illegal part.

Some of the reverse engineering being done by LLMs is using older OSS. I remember hearing about some 2012 era reverse engineering app that looks at the assembly language and reconstructs software. The LLM isn't reverse engineering itself in those scenarios, its calling local software, interpreting results, probably glueing software together with what the human is prompting it to do.