Comment by diggan
> After all, if I installed spying software on GM's computers, and sold the extracted data to, say, Toyota, I'd face hefty fines. And spend time in prison.
You're going about this all wrong. Setup a company, create a landing page and do some B2B contracts for selling that data, and you too can be a "Data Broker" fully legally. But yes, approaching this as an individual is most likely illegal, you're supposed to do it as a corporation.
IANAL but you’ll want a cofounder. Piercing the veil is a lot easier with a single founder company.