I went to a concert in Mannheim about 8 years ago. They had quite a few fairly reasonable rules, but they also had security guards to enforce them. If you brok

I went to a concert in Mannheim about 8 years ago. They had quite a few fairly reasonable rules, but they also had security guards to enforce them. If you broke any of the rules and refused to get your shit together they would pick your ass up and carry you out. You wouldn't even get a chance to leave. I think good security and enforcement of the rules would be a better solution than taking peoples' phones.