Noise, to provide cover for chatter and to keep the faint-hearted away.
No attribution, no sauce. Anon is anon.
People under NDAs and who hold active security clearances don't post Classified information.
People who put 2 and 2 together and infer information that might be classified haven't disclosed anything other than a potentially accurate opinion.
In other words, a person would have to KNOWINGLY disclose classified info before they could be subject to prosecution.