LOL..tell that to Martin Luther. Or do you even know who Martin Luther was? Probably not.
At the time of Luther, posting of announcements on church doors was common practice- it was like a community bulletin board. In Wittenberg, where Luther did this, it was the community center and a center of not only a religious institution, but a center of the political control of the church- ie, it was public property.
Now, you are dealing with private property and a third party don’t get to decide what you put on it or trespass at it.
If it wasn’t of questionable legality, why ‘dress and act like a ninja’ and ‘hide from the police’?
Oh, and I guess I should point out that the church that Luther nailed his thesis to the door was a church that he was a priest and teacher and he was posting these in response to an outside party, Johann Tetzel who was selling indulgences. So in essence, he was posting the thesis on property he had authority over. He didn’t go damage someone else’s property