If you see an old man walking around Tokyo wearing insane hats like this, don't be scared. That's just Harajuku Ojisan, and it's okay to take his picture. He's not protesting anything, or drinking the strange koolaid, or making a political statement, he's just enjoying his retirement.
Ojisan once worked as a mailman, but says he always wanted to be an actor. He never made it to the big screen, or the small screen, but he's had some success on smaller screens (he's made it onto thousands of digital cameras and cellphones). Harajuku Ojisan dresses in outlandish outfits-- usually featuring goldfish earrings and unusual hats covered in dolls-- and can be seen strolling around Harajuku and occasionally riding his bike in Yokohama.
He even has his own Flickr photo pool.