>If so, where do you propose the line exists?

The line is drawn where an actual crime is committed.

I'm not really a fan of pre-crime control measures, but that's a personal opinion.

On the 14th of June 2017, a gunman radicalized by Facebook shot a member of Congress, Steve Scalise, after asking about his political affiliation. This actual shooting which actually left Scalise in hospital fighting for his life with serious internal injuries which required multiple life-saving operations did not lead to any of the media hand-wringing about political violence that the storming of the Capitol - where the members of Congress who "feared for their lives" were barracaded securely away from the supposed potential threat, and the only person who got shot was one of the people storming the building - did. Instead, the Democrats and publications like the New York Times pushed a completely false narrative that actually, Scalise and his party were the ones that inspired the shooting of a member of Congress, falsely blaming the shooting of Gabby Giffords on them when in reality that had nothing to do with national partisan politics at all.

This isn't even a "both sides" thing, because I'm pretty sure there isn't any actual equivalent of the attack on Scalise but on the other side. It stands almost entirely alone in recent US political history, a uniquely awful example of America's political polarisation turning into a justification for violence and attempted assassination that came incredibly close to succeeding. (Also, I would be shocked if one of the things that radicalized the attacker wasn't false claims of presidential election rigging, just because they were so utterly pervasive on social media amongst people with his political affiliation back then.)

All the mainstream American media narratives about the dangers of political violence have nothing to do with actual political violence. It's a weapon they use against the political side they oppose and stop caring about or even become apologists for when the side they support is carrying out the violence.

> But do you agree we should stop it when their instrument of voicing said opinion goes from online forum to pitchforks and firearms?

Sure, believing any conspiracy theory is not a justification for breaking the law.

> If so, where do you propose the line exists?

The line is already clearly defined by the law. Ranting on Facebook about conspiracies (true or not) is legal. Nonviolent protests are legal. Storming the Capitol obviously isn't.