It’s safe to assume that Google, Yahoo, and other major Internet companies were not thrilled when the NSA began demanding that they hand over users’ data as part of the court-approved PRISM spying program.

But that was nothing compared to how they must be feeling now.

The Washington Post reports today that at the same time the NSA was requisitioning data from Google and Yahoo via PRISM, it was secretly intercepting far greater quantities of data behind their backs. In that project, known as MUSCULAR, the NSA allegedly somehow tapped into the fiber-optic links that connect Google and Yahoo’s data centers around the world. That allowed it to suck up absolutely massive amounts of information on foreigners and citizens alike, which it could then analyze at its leisure.

Tech companies’ responses to the PRISM revelations were almost uniformly measured and legalistic. But Google’s statement about MUSCULAR makes it clear the company is really steamed about this one. Google told the Post it is “troubled by allegations of the government intercepting traffic between our data centers, and we are not aware of this activity.”

NSA chief Keith Alexander was quick to dispute the report, or at least try to cast some doubt on it. It's conceivable that the Post has its facts wrong in some way or another. But given all that has come out so far, including intelligence officials' track record of forgetting key facts when confronted with awkward questions, it seems plausible that there's some truth to the allegations.

If so, among all the troubling facets of the story, one little hand-drawn image may end up as an enduring emblem of the NSA’s wanton disregard for digital privacy. In a presentation slide provided to the Post by leaker Edward Snowden, someone at the NSA apparently sketched a diagram showing the exact point at which it broke into Google’s cloud. And there they drew a little smiley face.

From the Post:

Two engineers with close ties to Google exploded in profanity when they saw the drawing. “I hope you publish this,” one of them said.

The Post did. In fact, it ran the sketch as the main image atop the Web version of its story. 

The smiley face might seem like a harmless quirk, but it’s more than that. It’s an indication that the NSA's agents did not regret having to break into major American corporations’ systems and steal their data. They relished it.

More broadly, it suggests that—contrary to what its leaders would have the public believe—the NSA’s agents did not undertake spying on untold millions of people around the world, including U.S. citizens, as a grave matter, unfortunate but necessary. It suggests they took it lightly—they thought it was funny.

Read the Washington Post's full report here.