This is more of a creative inquiry than anything. When I first started reading the EP book, I had already begun envisioning a character that would hack the mesh inserts of opponents in combat and use AR illusions to throw them off. Reading the hacking rules more closely, though, I was stymied by the 10 minute task action it takes to defeat a firewall. The game I played it in has since stopped, but we had a bunch of players that made AGI characters, so almost every physically sleeved character had a ghostrider module to accomodate them. We didn't have that many violent episodes, but the AGI characters did find themselves rather sidelined during those moments.
Now, I had trouble fully grasping the hacking rules and remembering everything that's required, so feel free to shoot any of this down, but a thought occured to me, which is actually mentioned on p. 299: Hacking the equipment of opponents, rather than hacking their mesh inserts directly. Since practically every piece of equipment has a wireless Voice for interfacing, I figure that when a person utilises it in that manner, a signal gets sent from the mesh inserts to the device, which can then be sniffed by a vigilant ghostrider and subsequently spoofed without taking the 10 minutes to deal with a firewall.
The obvious use of this is to either lock the gun of your opponent or just expend the magazine in a wild spray, but I have my doubts about whether EP characters use a wireless signal or a physical trigger to use a gun. I expect both options are available, and in the case of a smartlinked weapon, a wireless connection is probably obligatory. I suppose this adds a layer of security to using a physical trigger, since you're not sending a radio signal that can be sniffed.
As for other gear, if an opponent has an x-ray emitter or a flashlight of some sort, you could activate that to make an enemy reveal himself. An electronic rope could bind its owner and a spindle climber could fire and drag the person toward whatever wall he's facing.
tl;dr: What do you do with your opponent's equipment once you've hacked it?