The URL directs the users to Paypal and requests €5 in exchange for instructions that explain how to remove the hack. But how did he get in? By relying on users' forgetfulness. All iPhones have a default root password. Those who forget to change it are vulnerable to this very kind of attack.
Asking for money is kind of a bummer but much less obnoxious that other things he could have done. The moral of the story is pay attention and be thorough when jailbreaking your iPhone.
[Via Ars Technica]