I am extremely unlikely to ever allow anything even vaguely related to Elon Musk to implant something in my brain, or even to wear as completely noninvasive "through the skin" helmet or headband-like sensing device. Nevermind something with him as a founder.
I'm reminded of The Diamond Age novel, where a character hears about someone who had an implant which was hacked. If I recall correctly, the hack caused the implant to display an advertisement in a different language at the edge of their vision. That seems pretty benign compared to what a neural implant could be made to do to someone.
Black Mirror: https://en.wikipedia.org/wiki/Men_Against_Fire
just as an example