If the NSA is monitoring phone conversations for key words and phrases for tracking Foreign terror suspects, I believe that DHS and the FBI and probably several other of the alphabet agencies are monitoring gun forums and the like. There are enough people in the govt that see gun owners as a threat, I just assume that everything really controversial said on this and other gun forums is reviewed. You can bet that ATF probably has people who keep an eye out on the NFA discussion on the internet.
Think about it, if there is a post that amounts to "My buddy Jim-Bob showed me how to make my Thrustmaster 6400 into a full auto." I would think that a statement like that would set off an alarm bell or two somewhere.
We are seen as the enemy by the current crop of left wingers in govt (probably by past and future as well.) That's why when someone tells me they love their guns and Obama, I figure they are so naive (or stupid) they would have been a proud member of "Jews For Hitler" in that era.
Leftists will often come right out and tell you what they think of you and what they want to do to you. Much like the Jihadists, they have no problem telling you their goals. Why would you think they aren't serious about it? If more people had read and heeded what was written in Mein Kampf, things might not have gotten out of hand. BHO has written not one, but two autobiographies. That fact alone should give one pause as to what kind of narcissist we are dealing with. That's before we start discussing the contents.