China changes every day and so do the requirements for photographers. I've been in China many times before but the security measures during the 2008 Beijing Olympic Games were quite intense. Nowadays photographers – both employed by big news organizations or independent – are required to have some sort of journalists' IDs in China. The Beijing Olympics were not an exception.

During the Olympics virtually everyone from volunteers to journalists, engineers to policemen had to wear IDs--that left only tourists and ordinary residents. Just to photograph the atmosphere around the Olympic Games I decided to arm myself with a journalist pass even if it didn't grant entry to the Olympics venues.

There were roughly two kinds of media IDs: one was a BOCOG (Beijing Olympics Committee) ID that was yellow and red; the other one was a BIMC (Beijing International Media Center) ID with white and green. The colors of the straps were also an indicator of the IDs: yellow for BOCOG, and green for BIMC. I was too lazy to apply for the BOCOG ID, which required the approval from the IOC a long time ago, so I applied for the BIMC. A little something was better than nothing, I thought.

When I arrived in Beijing a week before the Opening Ceremony I went to the BIMC compound near the Bird's Nest, the National Olympic Stadium. The office already had my ID ready since I had uploaded my profile picture and other information via online application. With this ID I was not able to go in and out of the sports venues but I could prove that I was a journalist to the Chinese police and civilians.

On the morning of the opening day, Aug. 8, I went to Tiananmen Square on assignment for Der Spiegel magazine. At around 10 a.m. the sea of policemen suddenly began to clear out the area, pushing away hundreds of spectators who had gathered around the Olympic clock near the square. The police lined up in two parallel rows with their backs across from each other then began to split up and move the crowd. Spectators had no idea why they were being moved from the square because the only thing the police had said was "move, move!" Some plain-clothed policemen were trying to cover my camera lens as I was taking pictures of the scene. No one gave me a clear explanation even when I showed my green-and-white BIMC journalist ID. I assumed it had something to do with security on the Opening Day.

Later that afternoon, I learned that there was a luncheon by international dignitaries in nearby People's Hall and the crowd had to be removed. The need for a security measure had been heightened after the recent series of attacks in China's Xinjiang province.

Throughout the time of the Olympics I felt uptight about all the different types of security guards. But I understood why they had to react certain ways: the authorities did not want any kind of accident to occur during the Olympics. I just wished that they had given the journalists including myself more flexibility especially when they were wearing IDs.

I think not just China but the whole world is changing. It might be an inevitable step for all security to be more cautious and access for photographers, especially freelancers like me, to become more and more difficult after the events of 9/11 and the series of suicide attacks around the world.