When you connect to Wi-Fi, if no password is required to join the network, anyone can sniff your packets. This means that an eavesdropper within physical range of your network can listen in on anything that's sent or received. lf your iPhone is set to check email automatically, you might reveal sensitive data by joining such an open network, especially if you don't use SSL. (If you do use SSL, intercepted communications will be garbled by that encryption.) Under Settings > Wi-Fi, there’s an option called Ask to Join Networks. However, this option only does what it says the first time you connect; whether you have this option on or off, the iPhone will never ask before rejoining a network with the same name. So, if you visit a network with a common name, like "Linksys," your iPhone will automatically join every network it discovers with that name.
ln a single cab ride, you could unintentionally expose your iPhone to dozens of networks with the same name. if you use Wi-Fi at home, make sure your network has a unique name, so when you're away from home, you don't have to worry about someone else having the same name tor their Wi-Fi network. You can also tell the iPhone to stop automatically joining a nearby network by tapping Settings > Wi-Fi > The network’s name, then tapping Forget this Network. If you plan to join an open network and aren't using SSL. in email, turn off automatic email checks by tapping Settings > Fetch New Data > Manually. Then join the network, and don't check your email. Restrict your activity to things that don't reveal sensitive data, like reading websites or playing Hold'Em.
