Private propaganda is legal. Most is also exempt from Truth in Advertising Laws.
If Religion had to verify their claims, and were barred from telling you just how hot the fires you will be cast into, now or later, they would be reduced to, "Behold Maybe!"
At least the Russians got it right, the company line was published in Pravda, (Truth). Everyone agreed, for it is cold in Siberia.
Natasha, "I do not fear being sent to Siberia." Boris, "No?" Natasha, No, I fear what they will do to me, before sending me to Siberia." Boris, "Shudder."
It worked out because no one believed Pravda, and in The Workers Paradise, they had time to explore why that would not work.
It is a cycle, we are now in the time when the Secret Department of Evil Spirits finds it can not locate any evil spirits, so it goes after their friends and fellow travelers.
The House Committie on unAmerican Activities did the same.
in 1935 Harry Anslinger discovered that a product that had always been legal, to grow, smoke, or make rope out of, lead to Reefer Madness, and was the cause of all crime. Outlawing it lead to a crime free world.
The latest Thought Crimes are too vauge for Lawyers to explain to Judges, which is why the Government can detain people forever, and never let them see a Judge. Anyone asking about them can also vanish, for Freedom.
We have bigger problems than people lying to us.