BERLIN (Reuters) - Police in Berlin said on Wednesday they had arrested two men on suspicion of placing cement-filled soccer balls around the city and inviting people to kick them. At least two people injured themselves by kicking the balls, which were chained to lampposts and trees alongside the spray-painted message: "Can you kick it?" Police said they had identified a 26-year-old and a 29-year-old and had found a workshop in their apartment where they made the balls. The two are accused of causing serious physical injury, dangerous obstruction of traffic and causing injury through negligence, police said. Berlin hosts...