Sorry Sampo mentioned this thread elsewhere and I came back to it...
I will STRONGLY reiterate what Sampo has said. Even beyond that I will add a few things...
Re:19 VDC
It is still strong enough to penetrate the skin (Approx 10V give or take some, less when water is involved, thus why licking a 9V battery can give you a nice tingle on your tounge, and that is much lower amperage) and it doesn't take much electricity to screw with internal organs(Measured in miliamps). Admittedly it is DC which is safer than AC through organs such as the heart, but it is still NOT A GOOD THING!
Re: 3 Prong Power Supplies and when they showed up
They have existed, especially in the US, for quite some time. The reason you didn't see them as much on older laptops is the older laptops did not draw quite as much power in general if memory serves. You now have laptops drawing 300W in some cases, it is freaking ridiculous. So yes, as power requirements go up, danger increases and as a result safeties are put in place, aka ground wires in case a short happens so that that increased power goes to ground and NOT through your body.
Lifting the AC ground is a common solution, and is VERY WRONG!. It is a common solution not only in laptops, and desktops, but also on the live stage, where people die from it quite often unfortunatly because someone lifted an AC ground on a guitar amp.
Best solution is to isolate the audio grounds as Sampo mentioned. There are a couple of different ways of doing this, including 1:1 transformers, removing the ground wire on balanced connections on one end, etc. The transformer solution is prefered. There are rackmount units such as the ART T8 that will do this on multiple channels all at once.
You can, also as Sampo mentioned, institute a star wiring scheme in your studio where everything is fed from a single grounded outlet. If your studio is small enough to do this, it is a good idea if you are low on money. Keep in mind the power draw of your equipment vs what that outlet can give of course.
Seablade