Think of the absolute worst place of work you'd want someone looking at porn. A construction site? Nah. An emergency room? Nope. A confessional. Awkward... but guess again.

What about the office in the U.S. Department of Defense in charge of shooting down nuclear missiles? Bingo!

Last week the Missile Defense Agency issued a memo to staff members asking them to cool it on the porn during work hours. Bloomberg News got a hold of the letter on Wednesday, which read in part:

Specifically, there have been instances of employees and contractors accessing websites, or transmitting messages, containing pornographic or sexually explicit images...

These actions are not only unprofessional, they reflect time taken away from designated duties, are in clear violation of federal and DoD and regulations, consume network resources and can compromise the security of the network though the introduction of malware or malicious code.

The agency's executive director, John James Jr., who penned the memo, should take solace in the fact that his employees aren't alone. According to Nielsen, 21 million Americans accessed X-rated websites from work computers in March 2010, spending, on average, an hour and 45 minutes perusing porn during the month. That's about 29 percent of the U.S. work force -- and doesn't even count folks who sneak a peek or two on mobile device on the job.

And the Missile Defense Agency isn't alone among federal agencies. The Securities and Exchange Commission was caught with its pants down, metaphorically speaking, in 2010 when workers there were found to have been surfing pornographic websites during perhaps the worst period imaginable -- the late-2000s economic collapse.

But don't think the DoD or SEC are being prudes here. Really, they're concerned about malicious software getting downloaded onto government computers. As a Missile Defense Agency spokesperson told Bloomberg, "a few people downloading material from some websites that were known to have had virus and malware issues."

The Missile Defense Agency is in charge of developing and fielding the systems designed to counter ballistic missile attacks on the U.S. and its allies, according to its website.

We assume on-the-job distractions are discouraged in this line of work. Thankfully, "appropriate disciplinary action" was taken against perpetrators.

Earlier on HuffPost: