Don't want cyber-bullying on a mobile phone? Don't fucking own one or don't let others know about it. Hell stay away from all the online social networking crap while you're at it, you're just asking for it otherwise.
But if it's too late and all else fails:
* Get your attacker shitfaced somehow, or stalk them at a party.
* Take embarrassing photos while they're passed out, doing something stupid/illegal.
* Publish them online for everyone to see, with bonus commentary.
* ? ? ? ? ?
* PROFIT!
That will fuck up their career prospects for years to come, because guess what? Employers sometimes google your name and other personal information to do their own 'background' check on you.
Edit: There's only one fatal flaw in that plan, that is the target may be stupid enough to do that to themselves with their own friends. In that case, make sure their employers can always find it very easily, and perhaps spread some disturbing rumours.