The disappearance of recent thread raised a question in my mind. Is there any firm policy that members can read that explains the deletion of threads? I mean other than; it is done at management's discretion.

Sometimes a member or members will enter a thread and disrupt it by steering it off topic or by making statements which seem designed to provoke rather than add anything meaningful to the discussion. I sometimes suspect this happens when the offending member(s) disapproves of the topic and deliberately causes problems knowing that it is a way to get the whole thread deleted. Allowing that my theory has some credence, wouldn't it be in the interest of more members to excise the off topic or argumentative posts and allow the topic to continue among those with a serious interest rather than declaring the whole thread toxic and trashing it because of one unruly faction?

The only time an entire thread is removed is if it violates the rules of the Café. For example, a topic that is discussing religion or politics is a direct violation of the rules and will be removed. A single post violating the rules such as flaming, the use of profanity or posting a religious reply to an otherwise non-religious topic will be removed leaving the balance of the topic in tact.

Sometimes the topic isn't really deleted but only moved to a management review area. This happens when the topic has multiple violating posts or when a violationg post is quoted several times throughout the topic. We review the topic, remove all the offensive posts and return the topic. When we remove a post for a violation, we try to send a PM to the member so they know what they have done wrong.