meesekiller wrote:
Unless it was an electromagnet...it probably wasn't high power enough. Popular Mechanics recommends physically drilling holes in the disk. Hard drives are like black boxes they are virtually indestructible these days. And HCl would probably work too.
Just about any magnet will not do anything to the platters. Since they are essentially glass, HCL would do nothing, and drilling would have to be done VERY carefully.
Drilling an unopened HD would work well as the glass shards would remain inside of the case, but trying it on the platters alone is foolish at best and dangerous at the worst.