Actually, that quote was "formulated" by Eric S Raymond (to whom Theo was referring as "the originator of the statement"), and is only deceptively named "Linux's Law" [1] in "honor" of Linus Torvalds, which is ironic because it actually dishonors him by being invalid.

The point that Theo was making is that ESR talks and talks and types and types about many eyeballs looking at code, but when it comes down to actually auditing code, he never actually bothers, and neither do most other of his minions who are so quick to parrot his ill-conceived "Linux's Law".

Neither "enough eyeballs" nor "the right eyeballs" are a GIVEN, even for open source software. Google "Heartbleed".

"Not enough eyeballs" (or "ZERO eyeballs" as he loves to claim) are NOT a GIVEN for proprietary software, because you can license much proprietary source code, and some proprietary source code is available for you to read and audit for free, under licenses like Microsoft's "Shared Source" license.

https://en.wikipedia.org/wiki/Shared_source

And qualified eyeballs are NOT FREE, and usually very busy being well paid to look at much more interesting things than poorly written buggy code like OpenSSL. I doubt that Eric Raymond has contributed any of the profits from his books or VA Linux stocks to Theo De Raadt or anyone else who actually takes the long time and tedious effort to actually audit code.

The one time ESR actually did try to audit some code didn't go so well:

The little experience Raymond DOES have auditing code has been a total fiasco and embarrassing failure, since his understanding of the code was incompetent and deeply tainted by his preconceived political ideology and conspiracy theories about global warming, which was his only motivation for auditing the code in the first place. His sole quest was to discredit the scientists who warned about global warming. The code he found and highlighted was actually COMMENTED OUT, and he never addressed the fact that the scientists were vindicated.

http://rationalwiki.org/wiki/Eric_S._Raymond

>During the Climategate fiasco, Raymond's ability to read other peoples' source code (or at least his honesty about it) was called into question when he was caught quote-mining analysis software written by the CRU researchers, presenting a commented-out section of source code used for analyzing counterfactuals as evidence of deliberate data manipulation. When confronted with the fact that scientists as a general rule are scrupulously honest, Raymond claimed it was a case of an "error cascade," a concept that makes sense in computer science and other places where all data goes through a single potential failure point, but in areas where outside data and multiple lines of evidence are used for verification, doesn't entirely make sense. (He was curiously silent when all the researchers involved were exonerated of scientific misconduct.)

[1] https://en.wikipedia.org/wiki/Linus%27s_Law

Linus's Law is a claim about software development, named in honor of Linus Torvalds and formulated by Eric S. Raymond in his essay and book [redacted]. [...]

Validity

In Facts and Fallacies about Software Engineering, Robert Glass refers to the law as a "mantra" of the open source movement, but calls it a fallacy due to the lack of supporting evidence and because research has indicated that the rate at which additional bugs are uncovered does not scale linearly with the number of reviewers; rather, there is a small maximum number of useful reviewers, between two and four, and additional reviewers above this number uncover bugs at a much lower rate. While closed-source practitioners also promote stringent, independent code analysis during a software project's development, they focus on in-depth review by a few and not primarily the number of "eyeballs".

Although detection of even deliberately inserted flaws can be attributed to Raymond's claim, the persistence of the Heartbleed security bug in a critical piece of code for two years has been considered as a refutation of Raymond's dictum. Larry Seltzer suspects that the availability of source code may cause some developers and researchers to perform less extensive tests than they would with closed source software, making it easier for bugs to remain. In 2015, the Linux Foundation's executive director Jim Zemlin argued that the complexity of modern software has increased to such levels that specific resource allocation is desirable to improve its security. Regarding some of 2014's largest global open source software vulnerabilities, he says, "In these cases, the eyeballs weren't really looking". Large scale experiments or peer-reviewed surveys to test how well the mantra holds in practice have not been performed.

https://www.datamation.com/open-source/does-heartbleed-dispr...

https://www.esecurityplanet.com/open-source-security/why-all...