Right, actually. People who aren't law enforcement can't just walk into a court to ask a judge to give them a warrant to take action against a criminal. That is the job of the police. And it's the job of government to decide what constitutes breaking the law. In due time, governments will, in fact, decide that using real child porn to train AI models is illegal, and enforcing that law will remain the purpose of the police. It will never be the job of private citizens to prove it to a judge, or to do anything else to the criminal except report the crime.

Libertarian, anarchist, and sovereign citizen deulisional fantasies are not reality. The law is literally structured around not having random people enforcing the law or investigating crimes.