If the card supports wear leveling you can't be sure that it is wiped. -- “Progress isn't made by early risers. It's made by lazy men trying to find easier ways to do something.” ¯ Robert A. Heinlein
Well the SD Card Formatter actually performs a bulk erase before formatting assuming the card supports it and you ask it to.
quote:FULL (Erase): This option initializes the file system parameter in the card, and initializes all the user data areas (Initialize it by executing erase processing (data deletion) of the card to all the user data areas). This option has the possibility that it takes the format time long according to the capacity of card. There is something that doesn't support to the erase processing according to the SD interface device. The erase processing is skipped when "FULL (erase)" format type is selected in the unsupported environment. In this case it is same as selected QUICK option.
Some USB sticks can also be bulk erased/formatted with a utility provided by the manufacturer. I've used such in the past. That said you usually have to know the OEM to find the tool (if it exists).
That said you're correct that simply writing zeroes to the device using something like DBAN may not erase everything. -- Don't feed trolls--it only makes them grow!
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