Rich and powerful men whose power and influence were so great that they were a threat to the polis, or what we would call the state.
As they were famous for doing, the Greeks came up with a solution short of violence, and that solution created a word we still have in our language today, thousands of years later.
It was a procedure under the Athenian democracy in which any citizen could be expelled from the city-state of Athens for ten years. While some instances clearly expressed popular anger at the citizen, ostracism was often used preemptively. It was used as a way of neutralizing someone thought to be a threat to the state or potential tyrant. It has been called an "honorable exile" by scholar P. J. Rhodes.
Perhaps the behavior of these speech tyrants could be tempered with a ten year hiatus from running their companies, along with some of their like minded consiglieri?
The person nominated had ten days to leave the city. If he attempted to return, the penalty was death. Notably, the property of the man banished was not confiscated and there was no loss of status. After the ten years, he was allowed to return without stigma. It was possible for the assembly to recall an ostracised person ahead of time; before the Persian invasion of 479 BC, an amnesty was declared under which at least two ostracised leaders—Pericles' father Xanthippus and Aristides 'the Just'—are known to have returned. Similarly, Cimon, ostracised in 461 BC, was recalled during an emergency.
In one anecdote about Aristides, known as "the Just", who was ostracised in 482, an illiterate citizen, not recognising him, came up to ask him to write the name Aristides on his ostrakon. When Aristides asked why, the man replied it was because he was sick of hearing him being called "the Just". Aristides then manfully wrote his own name on the ostrakon.
I think Zuckerberg and Dorsey, in particular, need this. Perhaps we could all start a movement to scratch their name on a broken piece of pottery and mail it to their respective corporate headquarters, as a form of peaceful yet pointed political protest.