|Pittsburgh police in riot gear redeploy after confrontations with protestors near the Strip District in Pittsburgh, 24 Sep 2009|
The city of Pittsburgh looks and feels like a fortress. Streets lined with businesses and usually bustling with people are now boarded and empty, as thousands of law enforcement officials secure the area around the city's convention center, where the G20 leaders are meeting.
Not far away is the closest, authorized protest allowed by the city of Pittsburgh during the summit.
Tianlun Jian helped organize it to draw attention to the persecution of members of the Falun Gong spiritual movement in China.
Most groups that have permission to protest are media savvy and know how the news agencies that have descended on Pittsburgh can help spread the word about their causes.
Groups not authorized to protest are also trying to profit from the media presence.
Thousands of protesters loosely affiliated with what's called the Pittsburgh G20 Resistance Project gathered at Arsenal Park, about two miles from the convention center.
Albert Pertrarca decided to join the protest despite warnings from police that the gathering was unlawful.