When you hear a voice, feel pain or other tactile effects.
They read all functions of the brain. They know imagination, logic, intent, reasoning, and see how you do through visual-intention metering.
An a.i. is responsible and imitates voices of people you know or what your seeing through the network around you.
You can mess with it by overloading it with your brain power.
The only humans out there are monitoring data flows from mass samples and possibly are activating t.i.s to the abuse/monitoring programs gangstalkers get there orders from.