the future will be great <3 we place those electrodes on a regular base. There is even use in humans and there is research for years now and still, no magic has happened. The brain/neocortex is global structure and perception is a decentralized/distributed phenomenon, needling your cortex will not make anyone reading your mind.
But Google and Facebook can profile you and read your mind better than anybody could. They already can and have predicted pregnancy before the people even know they are pregnant.
That is so true, we don't fully realize the extent to which these tech giants are exploiting our privacy and personal data.