Re: Not just location data
I think the GDPR peeps missed a trick here -
IANAL, I could be completely wrong, after that disclaimer, I believe under GDPR if you contacted Google and told them you withdraw consent from the tracking, that would be sufficient notice of "withdrawal of consent". You are not obligated to follow the burdensome procedures that they put in place. If they are still tracking you after that then they could be in breach of GDPR.