Why ? Simply because researches have developed ways to use thoughts to operate computers and even move a wheelchair . In fact these researchers ARE the scientists . This is just their "publicity stunt" telling the world "Oh I care about humans but I just want a piece of their brain because I'm not brainy enough"
At some point this might seems as a breakthrough and even letting those who manage to hack the brain earn a Nobel prize. Whatever it is , as always my sarcastic comment would be , why in the world scientists / researches or charlie have the time to think of hacking / reading / harvesting / manipulating the chocolate brain factory . PLEASE think of ways to FEED people without the use of money and of course barter trading does not count .
Just look at Stewie up there , he can't handle all this and his head is about to explode *BOOM* .