I don't get what's shocking about this. If you have a consistent history of publishing a foreign government's state secrets that damage its national security, they're gonna spy on you. And before the nitpickers jump in on me, I believe whether or not Assange actually damaged US national security by publishing leaks is a decision best left to people who actually work in national security rather than armchair bystander…
It certainly damages your national security if other countries get information about unjustly interventions by your government. So whose fault could that be?