>"The cancer label warnings in California aren't violating any free speech"
That's because it's commercial speech [0] attached to a sale of a product, which gets a reduced level of protection. I'm don't think that you could, in the US, compel non-commercial software to express messages like "We trust this CA". Mozilla has a 1st amendment right to not trust to CA's, and to tell their users why they don't trust the CA; to boycott a CA; to implement this in code and ship it.
> Mozilla has a 1st amendment right to not trust to CA's, and to tell their users why they don't trust the CA; to boycott a CA; to implement this in code and ship it.
Nothing so far says that Mozilla can't tell its users that EU trusts this but Mozilla doesn't. However it is clear that it is intended to force Mozilla to at least gives the user the choice to trust EU on this.
The part where they're forced to provide the EU's alternative version is still compelled speech.
The decision of trusting or not trusting a CA has an expressive character; it's not pure machine math. Some of the decisions are political speech, even: "we don't like the policies of country X, therefore we'll boycott their root certificate". (Roughly characterized)
That's because it's commercial speech [0] attached to a sale of a product, which gets a reduced level of protection. I'm don't think that you could, in the US, compel non-commercial software to express messages like "We trust this CA". Mozilla has a 1st amendment right to not trust to CA's, and to tell their users why they don't trust the CA; to boycott a CA; to implement this in code and ship it.
[0] https://crsreports.congress.gov/product/pdf/IF/IF11072 ("The First Amendment: Categories of Speech")