GDPR implies EU residence and USA law enforcement has no power in the EU. So they’d have to ask EU law enforcement, which will deny the request because of the fascist reasoning (Negative comments are both legal in the EU and US). GDPR protects the user where US law enforcement would try and get the data from the ISP directly, which is not allowed to share it without consent or a warrant by local law enforcement.

(Also, in the EU you can not sign your rights away. This means that even if you agree to a ToS where you allegedly give consent, it still isn’t allowed. The GDPR and local law supersede).