Not satisfied with SpaceX and Tesla, Elon Musk shed light on Neuralink, his brain interface company that wants to develop “ultra-high bandwidth brain-machine interfaces to connect humans and computers.”

During a livestream Tuesday night, Musk explained that he hoped Neuralink could help treat brain disorders, preserve and enhance human brains, and eventually merge humans with artificial intelligence. The company is already working on a system that would allow paralyzed people to control artificial limbs using just their thoughts.

All of this relies on brain surgery — the company wants to implant a small computer called The Link behind a person’s ear in order to use the neural interface. Musk said he wants approval from the Food and Drug Administration (FDA) for human trials as early as 2020.

While Neuralink does sound like an exciting leap forward for human-computer relations, brain implants raise the specter of Black Mirror–esque privacy invasions and horror. We’ve got a few questions about how this would work – and if it’s even a good idea.

When it comes to private data, some of Silicon Valley’s biggest tech companies don’t have the best track record. Would Neuralink have access to your brain waves and any information that makes you unique if you’re using their neurological device? Could they sell that information to third parties? Is there any way to make sure your data stays local or would all of these devices need to connect to a cloud server?

All of this raises some fundamental concerns about your most private thoughts — and governments might have to step in with regulations quickly to prevent this technology from being abused.

If you have a brain implant, what stops it from being hacked? Almost any piece of hardware or software has vulnerabilities and hackers have been known to exploit them given half a chance. We’d love to know how Neuralink will protect people’s brain implants (and other devices, such as artificial limbs) from intrusion. It’s not just hackers reading your thoughts — what if a hacker can cause The Link implant to overheat or explode?

Everyone’s brain is different, so don’t expect learning how to control an artificial limb or phone with your mind to be something you can pick up easily. We don’t know if The Link will be plug and play or if it needs some kind of ramping-up period. Will the technology be better suited to some people’s brains than others? Will there be some kind of universal tutorial for using the device, or will there need to be specialized one-on-one instruction?

Musk said the Link could initially be installed by a custom-built robot under a local anesthetic. That sounds relatively simple (for brain surgery) — but if your brain implant stops working, do you need another round of surgery to replace it? Will that surgery cost extra? If the cost is prohibitive, someone might be stuck with a faulty link in their brain until they can afford to pay for a new one.

We all have nagging thoughts we can’t control — our anxieties and fears, or even a song that’s stuck in your head. How will Neuralink’s technology interpret those thoughts? Could you theoretically lose control of a limb or accidentally start playing a song on your phone if the wrong thought crosses your mind?

Despite being a billionaire mogul, Musk has made more than a few questionable decisions in the past. His 2018 tweet about taking Tesla private for $420 a share eventually led to him paying a $20 million fine to the Securities and Exchange Commission and stepping down as the company’s chairman — all over the impact the tweet had on the stock market. He got into a public spat with the British diver who helped rescue a group of boys trapped in a cave in Thailand. Buying Musk’s cars is one thing — giving him access to your brain comes with significantly more risks.

Of course, handing your brain over to any tech company will come with a whole slew of ramifications we haven’t even thought of yet. So while we’re excited about this technology, it’s prudent to be cautious as Silicon Valley starts poking and prodding at our brains.