True, but "connecting the dots" is much easier when it's your job, and something you've spent decades practicing.
Not to say that you're wrong, but there's no evidence to back you up. We might as well assume that the NSA is behind everything, ever.
It tends to work well from a prosecutorial POV as well because anyone who is accused by that process has little evidence to exclude them.
This certainly bolsters the claim that the NSA's surveillance is doing society good. I'm not comfortable with that, but there it is.
So we now have to prove a negative or the NSA did it? Logic has officially left the building.
No seriously, the whole parallel construction dialogue for NSA feeding DEA tips is exactly the situation suggested here. Why do you equate published journalism with hoaxes and factually devoid crazies. It is insulting to a fairly civil discussion.
We also know this is an incredibly high profile case. It's in the interests of the DEA and FBI to lean on their contacts in the NSA, even.
That said, the FBI is very good at what it does, and finding this sort of thing isn't just what the FBI does, it's what any investigator does. (I have personal experience with this area that I can't disclose, but trust me, everyone knows how to link usernames between websites.)