> so if they could reliably detect the browser at the TLS handshake stage (don't know if it's possible) It's possible and easy, the list of ciphers in the Clie

> so if they could reliably detect the browser at the TLS handshake stage (don't know if it's possible) It's possible and easy, the list of ciphers in the ClientHello is different. Take a look at https://www.ssllabs.com/ssltest/clients.html https://www.ssllabs.com/ssltest/clients.html to see what several popular browsers look like.