I would not doubt that gross emotional responses could be detected in humans. Like 'love of Big Brother' for example. I'm actually a little surprised that the technology does not exist now or if it does, that it's not used to ferret out the likes of Snowden before he was given root access to the machine.
Beyond that, I would not rule out the possibility that thoughts which are formulated through semi-vocal means within the mind might be tapped with some amount of precision. At some point anyway.
There are two options as far as I see it, either distant thought reading was already done in the WW2 period or humans will never achieve that, I like to think the latter. I do not believe in super-new secret airplanes, Aurora never existed, we live in a period of demagogism and scare tactics, to tell you the truth I have no reason to believe nuclear weapons exist either.
This is certainly a real threat although I doubt as to how effective it really is, kinda scary that someone can use one of the hundreds of your Windows backdoors, plant a trojan and read your mind ("read your mind" might be a bit far fetched), kinda violates you on a whole new level.