Technology

The law does not require photo ID uploads or facial recognition, with users instead simply self-reporting their age

That part is good at least. It also makes the California law an exercise in wasting everyone's time and money.

Technically, Linux is not an operating system, just a kernel, so I'm not sure how this would be implemented.

Yeah... no

I've always input my age as 1900-01-01 and I can't change that now because that'll show an inconsistency and we can't have that now can we.

Many people here are going off on wild tangents over this. You should just read the law, it's only a couple thousand words of quite plain English.

Many here have taken completely incorrect assumptions from the title. This law is for developers, not users.

Summary:

1. Requires OS devs ask for DOB, age, or both at account creation time.
2. Requires an API that allows app store devs to request this age data for the account. At minimum this API must signal that the account is a member of one of these categories: 'user under 13, user over 13 and under 16, user is over 16 and under 18, user is over 18'.
3. Explicitly bars OS devs from sending more data than explicitly necessary to meet 1 (hint: photo ID, facial recognition).
4. Explicitly bars app devs recieving the data from requesting more data from the OS nor the App store.
5. Bars app stores from using the data for any other reason and specifically calls out anticompetitive practices.
6. Bars app store and OS devs from sharing this data with any third party for any other reason than to comply with this law.
7. Has injunctions and civil penalties of $2500 (max per user) affected by negligent violations (eg a child account is served adult content), and $7500 (max per user) affected by intentional violations.

The only problem I have with this is that it should only apply to commercial software (app stores and OS). Libre/FOS software should not have to police ages on their app stores, due to their far reduced budgets (often zero), developer time, and the nature of the software being generally anti-centralized and anti-surveillance-capitalism. Though I'd be fine with it for FOSS software distributed via commercial app stores, as long as they gave a longer lead time to implement (EG a couple of years).

Will they patch useradd or adduser to support that?

Its parents that are pushing for this stupid shit. I hate that the majority of voters want to implement robust age verification.