Security

Nothing - by default.

Having said that you can:

• Add a password with E.setPassword
  
• Totally move the console device out the way with something like LoopbackA.setConsole(1)
  
• Respond to the NRF.connect event, check the address, and manually disconnect if you don't like it
  
• Totally disable the BLE UART service with NRF.setServices - which I'd suggest for anything remotely production-based
  
  

So a whole bunch of options really. Eventually there'll also be the ability to whitelist and also do Bonding (ensuring an encrypted connection) - but that's not in the firmware yet