This is absolutely absurd logic. DDoS attacks can and do cause measurable hundreds of thousands of dollars of damage. You had to have known that. You just choose to overlook the potential damage here because you support the cause.
Ridiculous analogies aren't helpful. Try something like.. how about standing in front of someone. All day. They can't walk anywhere without pushing past you. Basically harassment and interfering with their day. The damages lie solely in the fact that they aren't able to be productive.
