Unless the discs inside are literally destroyed, i.e. melted with a blow torch or something, there is ALWAYS a way to retrieve data off a hard drive. Even then, I would bet the NSA or some government agency would still be able to recover data. Even if the drive has "failed" and is not usable anymore, you can take the platters out and read the data in another device.
There is software that allows you to recover data after formatting your hdd. If you used a program like DBAN or Acronis to wipe it, you'll probably have to take it to a data recovery center. Hell, even a place like Best Buy Geek Squad can do this. They'll recover all your data for a cool 2 grand if you format the drive or it has failed.
I wish people would just not post about topics they have no knowledge about.