It happens all the time. Possibly a majority of all twitter bans over the last 5 years fit that description. Say racist thing like "Muslims should stay out of the USA" get banned by twitter for "inciting violence against a protected group".

In a way, all political advocacy consists of incitement of violence. Any law not ultimately backed up by the credible threat of violence is just a suggestion. If you don't pay your taxes for long enough, eventually federal agents with guns will come to take you to jail, and if you resist, they'll kill you.