It is easier to send police officers to a netizen who posts something than to simply deny the post as fake news and state what are the true facts.
A visit by police officers of course tends to intimidate most people. No amount of justifying that it was just a friendly visit could change that fact.
The net effect, of course, is to cower almost everyone into submission. When one knows that one’s post can get them in trouble with the authorities if they misunderstood it and they characterize it as criminal, most of us would prefer to just stay silent.