Seriously:

The collection or creation of the data isn’t what’s problematic—it’s when the data is used in ways that are harmful to individuals, collectives, or groups. And the problem is that that can happen very quickly.
An authoritarian government having access to it could use it to try to identify people who don’t show political adherence, for example. That’s a pretty quick and serious misuse of the data. Or trying to identify people who are neuroatypical, and discriminate against or segregate them. In a workplace, it could be used for dehumanization of individuals by subjecting them to neurosurveillance. All of that simultaneously becomes possible.