There are two safeguards I can think of to minimise the threat (which, since I think brain-technology interfaces are the next major breakthrough, is serious) are:
1) The interface has to be one-way. There should be no way for external devices to affect the brain's operation or the body's actions. It should be humans controlling technology only.
2) It has to be voluntary - that is, you have to be able to disable it instantly if it begins to malfunction and still live in society.







