[wkat4242]

Expressif also block some cool packet injection things like sending malformed packets in their firmware. Which is not illegal to offer. They probably are afraid of getting a bad reputation.

This is why open firmware can be really handy for the security community.

[rfoo]

Given that they are originated from China, I'm not surprised.

For a while (not any more though) you can't sell an ACR122U RFID card reader online in China, just because mfoc [1] supports it nicely and it got a reputation of "smart card cloner".

[1] https://github.com/nfc-tools/mfoc