They say that because there IS a chance that if you are wearing wool socks on high pile carpet while stroking a kitty, there may be some static buildup and if you for some reason touch the motherboard while doing it, it could take a shock like a normal computer.

I have known a guy who did it while slightly intoxicated, Still fine. I have done it on carpet while resting it on my bed, still fine.

If you want to upgrade the hard drive, look here.

http://forums.afterdawn.com/thread_view.cfm/366945

You still have to do the softmod in the first place to get the EEPROM dump, though after that you can install a new hard drive.