Waving a Magnet Near Your Hard Drive Wipes It

Hard disk drives use magnetic domains to store data, but modern drives employ sophisticated shielding (mu-metal enclosures) that protect the platters from external magnetic fields. Historic drives were more vulnerable, but early adopters of magnet-erasure as a data destruction method found the magnet must touch or come within millimetres of the HDD platter, waving a refrigerator magnet at a computer has no effect. Solid-state drives (SSDs), now dominant in laptops and phones, use electron charges, not magnetism, making them completely immune to magnetic fields. The myth propagates in movies as a dramatic data-deletion trope, but the reality is mundane: secure data destruction requires specialised encryption-key erasure, degaussing equipment (for old HDDs), or physical destruction. IT professionals recommend NIST-approved software overwrites or cryptographic approaches, never magnets.