For those that don't know, EMP stands for Electromagnetic Pulse. It's basically a burst of electromagnetic energy that travels in various wave forms. Lightning strikes, Microwaves, and and high altitude Nuclear Explosion can cause EMP. Although relatively harmless to people, it can literally fry any electronic device in an instant.
I was thinking of how Rockstar could release a device like this as another weapon to use. It would basically be like a sticky bomb where you can toss it somewhere, and it would stick. Hitting left would detonate it, and anyone, or anything caught within a certain radius would be affected. A person's PV, or any car would instantly be dead so to speak. Add to that, anyone caught in the blast would have not only their Radar scrambled, but Cell Phone disabled for a certain amount of time. So basically that person would be running blind for lets say 3mins, leaving them wide open for any kind of attack. Of course if the person that detonated the device got caught in the blast, he too would suffer from it's effects. Just a thought to add a bit of variety to Free Roam, and such.