In ancient times, when movies and music were stored on tapes and computers used floppy disks, we were told that magnets were basically the devil. Even watching VHS tapes over and over would eventually cause them to lose all their information. That’s because the tape and the disks themselves were magnetic. That’s how the data was stored.
Now, though, this old warning has become a modern-day myth with the digital memory cards we use in our DSLRs and mirrorless cameras today. But it turns out that no, magnets will have zero effect on your memory cards – even REALLY powerful ones, as proven by Braniac75.