The prevalence of suing in the US always surprises me. I wonder though: Can Kyle Zak (the plaintiff) be just anybody? Does he need to prove any damage occurred

The prevalence of suing in the US always surprises me. I wonder though: Can Kyle Zak (the plaintiff) be just anybody? Does he need to prove any damage occurred to him as a result, or is the violation of TOS enough? "Zak is seeking millions of dollars of damages for buyers of headphones and speakers" who would hypothetically get said millions? This doesn't seem to be a class action.