These kinds of internet attacks happen all the time to children who host Minecraft servers, small businesses, amateur programmers, etc. Finding the responsible party is often difficult if not impossible, and usually the FBI and other powers-that-be have bigger fish-to-fry (i.e., drug traffickers, cyber criminals who focus on extortion, etc) and are unable to devote resources to finding these types of attackers.
The sad reality is that a lot of people are unfairly attacked on the internet and many go unpunished due to lack of investigative focus, resources, etc.