Tokyo police are looking into an incident that disrupted traffic at a crowded intersection in Shibuya, a popular entertainment district in the Japanese capital.
Video footage posted on YouTube and Twitter late last month, shows a man lying on a bed covered by a blanket in the middle of the crowded intersection.
Four other men are seen placing the bed in the middle of the crossing.
The footage shows people gathering around to take photos. It also shows the men leaving the scene after tipping the bed over.
About 3,000 people cross the intersection with every green light.
Police say the people who carried out the stunt are suspected of disrupting pedestrians and violating the Road Traffic Law.
Last year, graduate students in Kyoto were arrested for sitting at a traditional Japanese "kotatsu" table in the middle of an intersection.
There have been many cases recently of people posting unusual footage online.
An office worker said it's not necessarily wrong to post such videos on the Internet, but he wants people to avoid causing trouble to others.
A high school girl said it's fun to watch things that are rarely seen in daily life, but that such acts could cause trouble and violate laws. She also said it would be unfortunate if the authorities regulated such videos.
A man in his 60s said such behavior is unthinkable for people of his generation, and that young people seem to want to be the center of attention. He stressed the need to educate people who take and post footage on the Internet.