If the police are able to implant a device into your brain to get information out of you, I think you're screwed either way as the good 'ol rubber hose method is likely on the table - at least until people commonly elect to do the surgery or the surgery somehow gets to legendary levels of safety in the dystopian future.
Nah. Generic brain reading is not possible in the forseeable future. Everyone's brain works differently. You have to train a machine learning model to recognize specific types of inputs. You likely cannot do pure thought reading.
If like the sibling said they develop on-skin electrodes or micro-needle patches I 100% agree.
Currently it requires an invasive and risky brain surgery which AFAIK would be a definite no-go. At least in the US, this would likely be considered extremely inhumane unless it could be done without such significant risk of death or brain damage - given the nature of the surgery I find that unlikely.
In the cases where an invasive brain surgery would be permitted, I imagine torture would already be an option. Keep in mind torture doesn't have nearly the same risk of death and permanent brain damage as an invasive brain surgery.
Ignoring the ethical and legal problems with torture, the main problem that is not usually portrayed in films is that people say whatever the interrogator wants to stop the pain.
interrogator> We have been torturing you for 10 hours. If you spell "John" we will stop torturing you and torture John instead.
interrogated> [The pain is too much. We have a deal. Sorry John.] JOHN
A better interrogator can be more subtle, like
interrogator> We have some evidence [1] that John is the one that put the bomb, and that you are innocent, but my boss is not sure. If you confirm this info we will send you immediately to your cell.
[1] It's a lie! Also, John is innocent in case you are wondering.
Oh that's interesting, make them think the thoughts at least for extraction. This first version of the tech requires the user to mentally imagine moving muscles to trace letters so yeah it's not likely to be an option... yet.
I wonder what happens to these BCI results when the user is on psychedelics a la MK Ultra
EDIT: Wait your point was slightly different then I first read but that makes perfect sense!