"Sec-GPC: 0" is invalid. The value can only be 1, and that explicitly cannot be changed in the future according to the spec.
This makes GPC a flag that means "unknown" or "opt-out". There is no "please share my data with your newsletter company" value, there can only be "do whatever the default is for sharing my data with any company you partner with".
This makes GPC a flag that means "unknown" or "opt-out". There is no "please share my data with your newsletter company" value, there can only be "do whatever the default is for sharing my data with any company you partner with".