The public square was in communities small enough where townspeople knew each other, and so speech was not anonymous besides those who penned (but not those who distributed) unattributed pamphlets. Moreover, if the speech you were pronouncing was beyond the pale of the community’s values, you could face retribution for it, whether judicial or extra-judicial like tarring and feathering. Even in the nascent USA whose political elite was high on Lockean ideas of natural rights and freedom of speech, the public square was never a free-for-all.