Loosely defined legal terms. A "computer program" can be copyrighted. You can write your own that does the same thing but you cannot copy the other code and slap your label on it. With a lot of imagination and bending the words of the shitty outdated law, you could say a website is also a "computer program." You cannot just go into the code and change it, e.g. by blocking ads. The lower court ruling didn't take this possible interpretation into account and now has to rule again with this in mind. Nothing's been decided yet. We're running a little hot in this thread on misleading headlines.