Sure but i guess "if" the 3 Letter Agencies really wanted to get an insight, it would not be that impractical anymore to even corrupt/steal/sniff a number of like 10k of MNs, as i guess a large % of MN are hosted in rather easy to access countries DCs. Given the afford and possibilities the NSA alone has... guess thats why other people in this thread were pointing to Snowden
OK let's look at the MN distribution today:


25% in the US, lots in Europe, the remainder in all sorts of places.
Let's assume, for the sake of argument, that all the US nodes are easily compromised. I don't agree with this, but let's assume it anyway. 75% of the network is still OK - Darksend is secure. To take the next big chunks they need to convince the French, Germans & Dutch...now I'm not sure how familiar anyone is with European politics but we're getting into some interesting territory here. Let's again assume this happens, for the sake of argument. Now 75% of the network is compromised and reporting activity back to the TLA, which is still not good enough to compromise Darksend with masternode blinding. Feel free to correct.
From here you're moving into Eastern Europe, China, Russia, Iceland etc. Different ball game as everyone knows.
We also need to consider the dynamic nature of the network. Nodes appear and disappear in different countries every day. TLAs would be playing whack-a-mole trying to break nodes, particularly if there was any hint that nodes were becoming compromised. In this case you could expect the community to be aggressive in moving nodes to 'safe havens'.
Finally - this is the picture TODAY. We are seeing trading volume coming in from China. If DRK topples LTC then this will seriously ramp up, then you will see many MNs in China. Just one example of how distribution may change over time.