Though jailbreaking an iPhone certainly opens up opportunities to add functionality that Apple doesn't approve of, it can also make an iPhone less secure. Several Dutch iPhone users found that out the hard way after a hacker attacked a number of vulnerable phones on T-mobile Netherlands and tried to extort €5 from them.
It appears one enterprising Dutch hacker used port scanning to identify jailbroken iPhones on T-mobile Netherlands with SSH running. Enabling SSH is a common procedure for jailbroken iPhones, allowing a user to log in via Terminal and run standard UNIX commands. Unfortunately, iPhones all have a default root password that many forget to change after jailbreaking, leaving their phone as vulnerable as a Lamborghini parked on a public street with the windows down, the doors unlocked, and the keys in the ignition.
