Of course many comments in this threas are exaggerated; there won't be played any ads into your brain.
But there are some implications for the usage of Neuralink that are worth thinking about it - especially when it comes to privacy:
Given that it "just" runs with firmware, so that the implant can function in a way most stable and reliably, and also given that there will be no subscription model involved into all of that, will the user (patient) be able to control the functionality of the implant (e.g. controlling the intensity of the eletric signal sent out from the implant to counteract the intensity of a tremor)?
And how will that happen? One thing I could think of is to control the implant with a smartphone app. How good will that smartphone app be? Will it be programmed sloppily like these apps we know from Internet-Of-Things-Apps and have a ton of bugs? Are those (medicinal!) apps secure in terms of privacy? What is with the product support? Will the implant be discontinued after a few years (and also the app)? What if your smartphone fails (no power or hardware failure, or after an update it doesn't work)?
A friend of mine has an app to monitor her blood sugar. She is not qute satified with the app. Luckily the provider of those diabetes sensors provided a separate device, so that the app is just an addition for measuring when you are travelling, for example. But in their last iteration they tried to omit the separate device, probably in order to save costs. My friend had to explicitly ask for it.
With that in mind I'm not keen on having control on such medicinal devices with a smartphone only. If the smartphone fails, there would be no backup. Will such similar things be the case regarding Neuralink?