He got off quite lucky. 1 year for a DDoS attack, especially lasting for a whole month, is nothing.
DDoS'ing usually goes under quite a few offenses, most notable in this case would probably be:
-Commercial rights (censoring)
-Loss of profits (which, depending on prosecution, can be more than just the here-and-now factual costs, but ramp up to statistical data of "assumed profit loss")
For private individuals, you could add a human rights violation. No one is to denie you internet access, if it is available to you.
DDoS'ing can be a serious offense. Looking at it commercially, it's probably one of the most fearful attacks, since there is no way to really avoid it, hurr, there are DDoS protecting services out there, durr hurr. Yes, but there is no technology to date that would stop a 'real' DDoS attack.
I'm talking thousands of sleeper/zombie computers (also referred to as botnets), all making use of various DDoS methods. One of the most notable was a Windows glitch (later fixed, but still took forever) where you would use the DateTime object to ping someone for 60.000 times extra the amount of data of the initial ping.
So, let's say you have the infrastructure to ping someone for 50.000 packets. That would be 50.000 x 60.000. Now add thousands of computers doing the same thing. Good luck repelling that attack. Bigger companies than Blizzard has been attacked, and completely shut down, making them lose staggering amounts of money. We're talking millions upon millions.
TLDR; DDoS'ing should be punished harder since there is no real method of avoiding it completely.
