Two examples: what im going to call the "im not touching you" type of harassment -- that is posting things clearly designed to hurt and wouldn't make sense in context unless designed for harassment. The platonic example here is the image macro that's the trans flag with the words "Your parents will burry you with the name they gave you". Cuel to the extreme, but doesn't technically call for violence against the given person, or the protected group at large so twitter and facebook, etc happily leave it up (and people wanting to be assholes hyper optimized pretty quick; ive seen the macro posted by multiple people in multiple places).
Second being the idea of stochastic terrorism. Painting a group as an unchecked evil means you don't have to tell anyone specifically they should commit violence, but, it's hard to be surprised if they come to that conclusion. See the shootings in Charleston or Christchurch.
Don't forget about Cesar Sayoc's mail bomb campaign[1].
This was a little gem in that article, seemingly highly relevant now:
> However, Rawls qualifies this with the assertion that under extraordinary circumstances in which constitutional safeguards do not suffice to ensure the security of the tolerant and the institutions of liberty, tolerant society has a reasonable right of self-preservation against acts of intolerance that would limit the liberty of others under a just constitution, and this supersedes the principle of tolerance. This should be done, however, only to preserve equal liberty – i.e., the liberties of the intolerant should be limited only insofar as they demonstrably limit the liberties of others: "While an intolerant sect does not itself have title to complain of intolerance, its freedom should be restricted only when the tolerant sincerely and with reason believe that their own security and that of the institutions of liberty are in danger."