Your hacker might start dodging in cybercombat.

Zomgz! The beginning of simsense! So apparently, you don't need to wire directly into someone's brain to make them feel like they're someone else, all you need to do is create a visual illusion. Which is not surprising considering what I know about cognitive neuroscience, and IMAX theaters

so basically, vr goggles and a virtual image of ones hand being poked at the same time as the real one (via a sensory glove maybe) so that from then on, when one move ones hand, the virtual hand moves and one thing its ones real hand.

could get messy in the long run if one cant find the will to go back to the real world

It's a little bit more complex than that, but you only need to add a few physical sensations at the beginning to make the participant actually identify the external viewpoint as their body. That occurs even when people totally understand the external nature of the input; the subjects in the experiment know what is happening, know that nobody intends them any harm but still react as if the mannequin is their own body.

I wonder how jaded people in 2070 are to this kind of effect.