I think that for a thread to be considered SPAM, it has to have little to no original content of any substance and posted with the intention of spreading a message as opposed to starting a discussion. The same could probably be said of posts, but I'd say the criteria apply more rigidly to thread creations, since they will set the bar for the conversation, if any, to ensue.

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"Government big enough to supply everything you need is big enough to take everything you have... The course of history shows that as a government grows, liberty decreases."

-Thomas Jefferson