Consider Enabling Global Privacy Control (GPC) by default

[xe-3]

Global Privacy Control (GPC) should be enabled by default.

As of Firefox 120, Firefox has enabled GPC by default for private browsing mode:

privacy.globalprivacycontrol.functionality.enabled true privacy.globalprivacycontrol.pbmode.enabled true

Firefox has not, and probably will not enable it by default for all users, because as a mainstream browser, doing so would be against the wishes and intent of the GPC designers, and could possibly undermine the effectiveness of the GPC. (The GPC is intended to represent an affirmative user choice, hence why it is enabled in PB mode by default but not normal mode, as anyone choosing to use PB mode is expressing a deliberate preference for privacy).

For Mullvad Browser that is not the case, the California law that laid the groundwork for the GPC, consider a user choosing to use a privacy-by-design product or service to be an affirmative user choice. Mullvad Browser is clearly and explicitly a privacy-by-design product so it is not constrained in the same way that upstream Firefox is, and other Private-by-design browsers such as Brave have already enabled GPC by default.

Enabling GPC will benefit users in the growing number of jurisdictions where GPC is legally enforceable, and should have no negative impact on users from other jurisdictions. Enabling GPC for all users will allow users who wish to use the GPC to do without negatively impacting their browser fingerprint.

I propose that Mullvad Browser sets this pref to true:

privacy.globalprivacycontrol.enabled

in addition to the two prefs which have already been enabled upstream:

privacy.globalprivacycontrol.functionality.enabled privacy.globalprivacycontrol.pbmode.enabled