Originally Posted by ScandaLeX
The manager at Sprint told me to have a magnet in/on/near the phone can cause damage to the sd card. He also said it's the reason why devices that have a magnet don't have expandable storage.
Now, I will admit, I don't have any idea if there's any truth to that. What I do know is I've had my GS2 and iPad 2 on my lap at the same time and nothing ever happened to my sd card.
Sounds like a typical salesman
Not saying that there isn't some small bit of truth to what he said but Flash Memory is much much less susceptible to a magnetic field than the old Hard Disks and Floppy Disks (even modern hard drives require a lab grade magnet to wipe data). There may be other small metal components that would be more susceptible to a magnetic field in a phone than the MicroSD or eMMC memory.
5,000 Gauss is the approx. magnetic power of a low end MRI machine.
10,000 Gauss = 1 Tesla