You can set password on your ZTE smartbro pocket wifi first go onto your internet browser type
http://192.168.1.1
( or what ever the default ip is for it. if your not sure what it is, connect to it with a laptop, press the start button, type cmd, then type " ipconfig " and look for "Default Gateway " followed by the IP number.)
Assuming you've logged into it you should see a login page. Enter the password smartbro as default. After log-in go to settings, select wifi setting, click security. Under this change the security mode from No encryption to WPA PSK/ WPA 2 PSK. Then you can now put your own password and click Apply.
Hope this helps