[Geewiz]

If you can't spin the disc over readers without damage to the readers (because the disc was drilled with a slow drill) makes it harder and costlier to obtain data...also, saltwater and/or corrosive chemicals further limits data recovery. Of course, if NSA believes your data to be a national security issue then cost and difficulty do not factor in and they will recover the littlest bits of data and turn it over to the FBI who has experts who can make sense of the smallest amount of raw intelligence. That said...labeling the disc - "Little Bobby's Bar Mitzva" will likely curtail their efforts.