What technical measures can consumers use to protect themselves against unwanted RFID reading?

A Faraday cage (shielded wallet/sleeve — the most effective), an RFID sensor detector (warns of read attempts), active jamming (blocker tags), and an RFID zapper (permanently destroys a chip — only on your own tags!).

Consumer self-protection against unwanted RFID reads:

• Faraday cage: special sleeves/wallets/backpacks of conductive material that fully block electromagnetic fields — the most effective method.
• RFID sensor detector: small devices that detect nearby read attempts and warn the user, enabling a conscious response (good for awareness).
• Active jamming: blocker tags emit interference that blocks legitimate readers; can also be a "privacy bit." Legal status unclear in some countries.
• RFID zapper: destroys an RFID chip permanently via high-voltage pulses. After "zapping," the chip is dead. Only suitable for your own tags, not others'!

Tip: A Faraday sleeve is the simplest, legal, reversible protection — it blocks reads only while the card is inside, so you stay in control. A zapper is the nuclear option (irreversible, and illegal to use on others' tags).