I think there is some truth to that but I'd say the one difference between speech recognition and brain recognition is that speech is a voluntary action you control, while your thoughts have a largely involuntary component to it. Involuntary meaning when someone says "an idea just popped into my head" - the idea seemingly was not an action deliberately triggered. Think if while you were "mind typing" an email and suddenly the thought "god I hate my boss" popped into your head. If the filtering mechanism of the computer was poor, your computer might, assuming it was being helpful, shoot off an email to your boss saying "god I hate you". I guess what I'm saying is the way by which you could filter your own thoughts to be interpreted by your computer or not seems like an incredibly difficult proposition.