China has blocked a number of websites before, for a variety of reasons, but observers believe that last week marked the first time that an entire country has been blocked by the "Great Firewall".

According to reports on Yahoo Japan, sites with a "co.jp" top domain were blocked for around a day and a half over June 15 and 16.

China and Japan enjoy a bitter regional rivalry of course, but quite why the co.jp domain was blocked remains a mystery. Tech blogger William Long has pointed out Japanese sites with ".com" and ".jp" domains had not been blocked, perhaps implying that the move was simply a mistake.

Of course, this being China, there's also a much more fun, conspiratorial theory. And of course, it involves the incredible scandal of ousted Chongqing party boss Bo Xilai.

Multiple Weibo users have pointed towards the possible interference of "Headmaster Fang" — the un complementary nickname for Fang Binxing, the man behind China's incredible online censorship project

Jimmy at Tea Leaf Nation has put together a great summary of the crazy "Headmaster Fang" theory.

Basically — Headmaster Fang himself grew extremely angry at Japanese newspaper Yomiuri Shimbun after it reported that he personally had a link to former Chongqing police chief Wang Lijun's US consulate visit in February (the incident that sparked the whole Bo Xilai controversy) and also may have played a role in Bo's alleged surveillance of senior Communist Party officials (including President Hu Jintao).

He then used his power to block all Japanese domains for an day and a half before something (higher powers in Beijing?) prompted him to stop.

It's clear that Fang was outraged — he expressed his anger on Weibo and called for an investigation — but the idea of him personally (and presumably, without the Party's consent) banning all Japan's domains with the push of a button really seems crazy.

But then again....

Watch the video below for a refresher of what happened to Communist bigwig Bo Xilai and his fall from grace:

Produced by Daniel Goodman