The current USBnetworking policy, as recommended in the README_FIRST.txt file and supported in the scripting, is too use only pub-key authentication over Wifi.
Ah, but guess what is the most popular port in the world to attack:
(ssh == port 22, telnet == port 23):
https://isc.sans.edu/top10.html
And port 21 (ftp) gets at least an honorable mention.
(Click the port numbers in that summary report for details.)