It would seem that you’d have to be pretty stupid to:
- Join any wi-fi network that has an SSID of “%p%s%s%s%s%n”.
OR
- Name your wi-fi SSID to be “%p%s%s%s%s%n”.
But if you did (why the fuck would you anyway?), your ability to use ANY wi-fi would be not possible until you reset your network settings in your iPhone by:
Open the Settings app, tap General -> Reset, then tap Reset Network Settings and confirm the request at the prompt.
Anyway, those of you who are either morbidly curious, or downright stupid can have a go at it.
The article on the MacRumors site goes into detail.