DDoS is illegal, but difficult to prove. It requires loads of knowledge as well as many resources. To successfully do a DDoS you require at least several hundred if not over 1,000 systems running your script. Proper DDoS attacks are difficult to actually locate the person who is doing it since they use a script ran on machines they don't even own. Chances are slim that he/her/them even have the ability to execute this kind of an attack, since it requires so many computers, and most kids don't have the resources to spread the required software to machines for use in their attacks. It also requires some level of expertise with networking. Lastly there is nothing that can be done until 1. he HAS executed the attack, and 2. you have located him and pinpointed the source of the attack (usually they hide behind a proxy, and you need to execute an accurate traceroute to locate the source)
