22
Fuck ads, obviously, but I can understand there's confusion here.
If GPC says "do not sell my data", but the user subsequently opts in via the cookie banner (or vice-versa), you have two conflicting signals. There's no clear case law or anything that says what to do. Or what should happen if the same user sends different GPC signals depending on their device or browser.
Although I guess the easiest solution is just "do not sell data if any signal suggests it's not allowed", but that doesn't line advertisers' pockets I guess.