This question already has an answer here:
As per the title, would these magnets
be enough to damage a portable hard drive such as this Seagate GoFlex
if left next to each other for longer than, say, 20 minutes?
Thankfully, this is all hypothetical at this point as I have kept them apart to date and my question comes to mind if the two fell on top of one another whilst in a backpack or bag.