If a WLAN network has a certain character combination, you should not connect your iPhone to it under any circumstances.
After we warned you a few weeks ago about a strange Wi-Fi network that permanently disables your iPhone's Wi-Fi connection, there is now another one. Twitter user Carl Schou discovered that the network: %secretclub%power completely wipes out your iPhone's ability to connect to a WLAN.
This new network is something of a variation on the original explosive Service Set Identifier (SSID). The original network was an apparent string of letters and the percent sign - %p%s%s%s%n - but as you can see in the new network, there is a common denominator: %p and %s. It's unclear whether both need to be used, but one or both of these pairs seem to be the culprits and it doesn't seem to matter where they are in the SSID. So stay away from them.
Schou says that, like the original network, connecting to %secretclub%power completely disabled his iPhone's Wi-Fi functionality, even after rebooting and resetting the network settings. He was only able to restore network functionality by manually editing an iPhone backup and removing "malicious entries" from the .plist of known networks. He also contacted Apple's security team about the problem.
As always, it is not a good idea to connect to unknown Wi-Fi networks, but it is also advisable to avoid using %s and %p when naming your SSID. (Macwelt)