Truncation: The browser could have warned users for years already. Pasting something that gets cut off is data loss. Relying on a JavaScript implementation to d

Truncation: The browser could have warned users for years already. Pasting something that gets cut off is data loss. Relying on a JavaScript implementation to do this is a hack that only covers some sites (yes, you could have an add-on, but no, that would require JavaScript, and it's still a hack). Binary Passwords: I could just copy/paste blocks of hexadecimal digits into the password field using a fixed number of digits corresponding with the key size, and they would be interpreted as a stream of unsigned binary octets. The only thing you'd need to know was the length. A suitable format is using hexadecimal. If you're using a password manager, you already don't care about what the characters are, only that it is secure. Passwords are also no longer limited to use printable characters. How would you implement that for all users? Adding a prefix like 0x to enter hex mode?