Japan is almost completely unbound by political correctness when it comes to Muslims. There have been no instances of Islamic terrorism there, mostly because Japan does not permit immigration without marriage to a Japanese citizen. There are some illegal aliens from Muslim counties working in Japan, but very few with families.

So the common sense notion that if you want to prevent Islamic terror, you watch Muslims for signs of trouble, is accepted popularly, and even at the highest levels of Japan’s judiciary. Thus, as the UK Independent writes (via MSN):

Japan's Supreme Court has upheld the government's blanket surveillance of the country's Muslim community.

The court struck down the second appeal by Japanese Muslim plaintiffs against what they perceive as an unconstitutional invasion of their privacy and freedom of religion.

The surveillance came to light because of a leak:

A 2010 leak of 114 police files revealed nationwide surveillance of Japanese Muslims. The files revealed that Muslim places of worship, halal restaurants and Islam-related organisations across the capital, Tokyo, were being monitored.

The plaintiffs were awarded damages of under one million dollars (90 million yen) for invasion of privacy because of the leak (not the surveillance itself). So it is a pyrrhic victory for them, leaving in place the legal mechanism for blanket surveillance based in the statistical probability that almost 100% of cases of Islamic terror are perpetrated by Muslims.

And who knows, maybe because the Koran preaches violent jihad against infidels, anyone adhering to its literal teachings is worthy of scrutiny.