The danger in 'clear and present danger' of yelling in the crowded theater is specifically and intentionally causing panic where people are likely to get hurt. As others have mentioned, though, it's complicated. The original poster was suggesting we need new laws targeting the amplification of social media, which could limit false and damaging speech. My suggestion is that existing speech, slander, and libel laws apply. The 'amplification' of social media gives individual voices more reach and clout, similar to yelling. Social etiquette, law enforcement, and the judicial system have yet to adapt.