IIUC, there are hard rules about admissibility of evidence, and you're aware when an attempt is made to use evidence that way, and have an opportunity to argue

IIUC, there are hard rules about admissibility of evidence, and you're aware when an attempt is made to use evidence that way, and have an opportunity to argue it, in a very enforceable way. Are there analogous rules around the DNA sent to 23andMe, would you have an enforceable opportunity to block uses of that, and would you even know when they're using it that way?