From Harry Potter and the Order of the Phoenix
It appears there is a connection between the Dark Lord's mind and your own. Whether he is, as yet, aware of this connection is for the moment unclear. Pray he remains ignorant.
You mean if he knows about it then, he'll be able to read my mind.
Read it, control it, unhinge it. In the past it was often the Dark Lord's pleasure to invade the minds of his victims, creating visions designed to torture them into madness. Only after extracting the last exquisite ounce of agony, only when he had them litterly begging for death would he finally...