As the other reply mentioned, another valid inference would be "it's not clear [that] YouTube can stop him." And as a general rule of thumb, you almost never ac

As the other reply mentioned, another valid inference would be "it's not clear [that] YouTube can stop him." And as a general rule of thumb, you almost never actually need a grammatical "that"-- it's best to leave it out for brevity unless it's useful to distinguish the meaning of the sentence (typically when the parts before and after it are longer and the demarcation point could be interpreted several ways without it). It's definitely valid as-is. It's debatable whether it's unclear (what would the alternative meaning be if you think it's unclear?)