"Stochastic terrorism" is the idea that if you spread fear and mistrust against a target, then eventually people will commit violence against that target, and it will be your fault, even if you never specifically said the words "you should commit violence".

Some other popular examples of the concept:

Nativists spread fear and mistrust about Muslim immigrants, and then racists go on shooting sprees in mosques.
The #Resistance insists that Donald Trump would destroy democracy, and then various people try to assassinate Donald Trump.
Conservatives spread fear and mistrust about transgender people, and then bigots commit hate crimes against transgender people.
Woke people say the police are racist and brutal, and then other woke people murder police officers.
Socialists call health insurance companies greedy and accuse them of blocking life-saving treatment, and then Luigi Mangione murdered a health insurance CEO.
AI safety activists say that Sam Altman's AI could destroy humanity, and then a guy threw a Molotov cocktail at Sam Altman's house.
Liberals said that Charlie Kirk was a hatemonger who was driving Americans apart, and then an assassin murdered Charlie Kirk.
The pro-life movement describes abortion as murder, and then pro-life activists assassinated abortion doctors and pro-choice politicians.

The "stochastic terrorism" concept is near-unique in how effectively it can be discredited merely by listing many examples of its use together in the same place. Almost no one supports a blanket prohibition on criticizing of all of these different groups of people. "Stochastic terrorism" mostly gets deployed opportunistically, by people who either are too blinkered to realize that the same argument could be leveraged against their own speech, or who hope you're too blinkered to realize that.

(in fact, one could argue that accusing someone of stochastic terrorism is itself stochastic terrorism! Here in America, we consider it justified to kill terrorists before they can threaten us further. Reclassifying criticism as terrorism implies it is potentially legitimate to apply the same norm to any especially harsh critics!)

Still, a sliver of concept-users make some fig-leaf argument that the cases they approve of are different than the cases they disapprove of. Some proposed principles:

https://www.astralcodexten.com/p/against-stochastic-terrorism