This power allows you to put a particular curse on anyone you want. The curse is that their thoughts are no longer confined in their own mind and can therefore be perceived by anyone in their vicinity. How big that vicinity is depends on the emotional state of the accursed, ranging from tens of meters to tens of kilometers. The victim usually won't realize they've been cursed until they've been told so or they notice people's reaction. Only the person who put that curse can lift it.