It’s not possible for Valve to solve with the way Valve usually approaches problems. There’s no easy way around it: you gotta scale up and do manual, human review. Algorithms and automation can’t make these judgement calls. It’s gotta be manual, it’s got to be flexible enough to get around trolling and false positives. It won’t be perfect, but no one is asking for perfection. Just a proper store and (if caught as a false positive) a reasonable response time.