How accurate is this: > “Tiananmen Square Massacre is a taboo subject, most Chinese under the age of 25 have never even heard about it. Websites that mention t

How accurate is this: > “Tiananmen Square Massacre is a taboo subject, most Chinese under the age of 25 have never even heard about it. Websites that mention the "June 4 Incident" are blocked in China.”? Is it really that burried?