I just checked my Github settings, and found that sharing my data was "enabled".
This setting does not represent my wishes and I definitely would not have set it that way on purpose. It was either defaulted that way, or when the option was presented to me I configured it the opposite of how I intended.
Fortunately, none of the work I do these days with Copilot enabled is sensitive (if it was I would have been much more paranoid).
I'm in the USA and pay for Copilot as an individual.
Shit like this is why I pay for duck.ai where the main selling point is that the product is private by default.