Lots of people believe bitcoin is scam and they are posting on this forum as well. When you will read this thread which has made on July 13, 2012 called "
A Scam" then you will discover few people believed bitcoin is scam. But all comments still alive and you are able to read them. So is it not freedom of speech? But you are trying to create FUD and repeating same thing again and again. So I believe someone reported your posts.
Probably your posts have been deleting below reason;
Q: Do you moderate/delete (possible) FUD, accusations and untrue information?
A: No. We don't have enough time to check every single piece of information and verify the validity of the sources. Also, just like scams - too much room for bias and abuse.
However, trolling isn't allowed. If a user is habitually posting obviously false nonsense ("obviously false nonsense" to an outsider, NOT to someone who follows or is involved in the discussion) just to stir up trouble, then it's considered trolling, which is prohibited. Such cases should be thoroughly documented in the report though (There are tons of reports that just say "trolling", but moderators don't have time to look through each user's post).