1. Silk Road sells guns.
2. The US has a 30 year war on drugs.
3. Profit (or not).

30 years ago NDAA didn't exist

The goal would not be to track individuals but to destroy Tor, Bitcoin and Silk Road

It will only require one claim that a gun sold by Silk Road ended up in hands of a terrorist. And by the way, NDAA directly violates 6th amendment, so appeal to constitution worth nothing.

Not possible, sellers on Silk Road have ratings much like eBuy, and customers can leave comments about transactions.

Not positive feedback...

But seriously the gov can build up a good reputation too. Not that I think they are yet, and even when they do it'll probably be to watch and learn mostly.

Hitting random bitcoin users would be pretty lol. Are they going to admit it's some random bitcoin or TOR user? Hope people figure it out and get scared? Maybe messing with high profile users would matter some, but does that scare people really?

It won't be a conspiracy scheme, just bureaucrats who would  honestly try to do their job better.

I think that's a valid point. It all depends on how deep US will be. If only one or two people detained at any given moment, then you right, it won't matter much, but US democracy is in downfall and several years from now the scenario could become possible.

Priorities?? Illegal activities are happening every second. Terrorism is a major priority for the US government, while Silk Road actually solves problems regarding to the drug industry for governments(no violence and higher quality drugs(lower risk to users) due to feedback).

What makes you think so? I do think governments, especially the US government, are not rational in their decisions, but they aren't completely stupid as well. There is only one senator who caught some attention about this subject, but as far as we can see nothing has changed but SR being more well-known. I do think allowing guns to be sold is a bad way to go for SR, I hope they reconsider changing back to their former policy.

Also, not all US conservatives think the same about drugs, this judge has some great points and they should be heard more often:
http://www.youtube.com/watch?v=b6t1EM4Onao

Without drugs there wouldn't be any society http://en.wikipedia.org/wiki/Stoned_ape_theory#.22Stoned_Ape.22_theory_of_human_evolution
http://en.wikipedia.org/wiki/Entheogens