Supposed you have DroidSheep Guard installed on your phone, this site shows how to configure and use it.
This is the screen shown after installing DroidSheep Guard.
So let´s go through the settings:
Autostart/-stop depending WiFi
This setting makes the app start automatically in case WiFi is enabled or disabled. So enabling this setting makes DroidSheep Guard shutdown automatically in case WiFi is disabled or in Power Saving mode.
Disable WiFi on alert
In case an alert is triggered by DroidSheep Guard, the app will automatically and immediately disable WiFi and shut down the connection. This will prevent theft of your accounts. Nevertheless: You should log-off all sessions you´re currently using when this message occurs – just in case.
Notify in system
This will enable or disable system notifications. Notifications will be shown in these cases: ‘DroidSheep Guard running, WiFi enabled’, ‘DroidSheep Guard not running, WiFi enabled’, ‘DroidSheep Guard running, WiFi disabled’.
DroidSheep Guard normally monitors MAC addresses. In case Cautious mode is enabled, DroidSheep Guard will also monitor IP addresses. This will on the one hand increase your security, on the other hand, it MIGHT cause false alerts.
Checks per Minute
This setting defines the frequency of checks. In order to identify attacks when connecting to a network, it is recommended to leave this setting at 60 checks per minute.
So if you keep standard settings, it should be enough to start DroidSheep Guard and enable autostart mode.
This if the View you´ll see in case an attack has been identified.
It is strongly recommended to disconnect from the WiFi to protect your sessions!
In some unlikely cases, this warning can appear although no attack is running. But if this warning is shown in a public WiFi you should disconnect and prefer using your phones 3G internet connection.