That's par for the course, really. Embassies and diplomats, etc, are all really just a kind of gentlemen's agreement to allow low level intelligence gathering. Every country does it, and every country knows that every other country does it. If it makes you feel any better, from a military and intelligence perspective, the US honestly has no closer ally than Canada.
As for Wikileaks, my personal opinion is that this guy is a pipsqueak with a chip on his shoulder. He's outed some intel in the hopes of harming the interests of the US, and it didn't work. The fact that he hasn't turned up dead in a car accident is a testament to the US playing fairly, and a blow to every conspiracy theory, "government faked 9/11" nutjob out there.
I do hope he gets his, though.