A weed grows in prison

I'd imagine it's hard enough for prison guards to keep people from smuggling in drugs, but when the drugs are actually growing inside the prison, well..

A Japanese prison is scrambling to eradicate marijuana plants that keep sprouting up on its exercise ground, officials said Tuesday.

The marijuana plants started sprouting at Abashiri Prison on Japan's northernmost island of Hokkaido about a year ago, said prison official Takeshi Okamura. He said officials plucked out as many as 300 marijuana plants and treated the ground last year, but several more sprouted again this year.

Now, that's unusual enough, but check this out:

Prisoners reported them to the guards.

Those must be some of the most ethical convicted felons on the face of the Earth.