If video is going to be streamed in China, the state wants to know about it. China requires a streaming company to obtain a state license and then avoid airing clips that might inspire fear, contain pornography, or endanger national security. That's a huge burden for sites that feature user-generated content, especially when "endangering national security" includes showing video clips of Chinese unrest. This week, China mounted a crackdown on 62 separate web sites that in violated a new law against showing online audio and video without permits.

When the government first instituted the law back in January, Internet video sites had already become hugely popular in China, and it was widely suspected that the rules would not be strictly enforced. At first, these suspicions appeared justified, as nothing happened for two months, even to the many sites that never bothered to obtain the state license to broadcast.

But yesterday, authorities penalized 32 sites for infractions, shut down 25 more for not having a license, and referred five cases to another department for follow-up. It was a fairly gutsy display of central control, one that may have been hastened in part by recent protests in Tibet (China recently blocked YouTube access over clips from Tibet that were appearing on the service).

It's not that the ruling Communist Party doesn't like online multimedia services; it does. Even capitalist advertising, which is surging in China, is no problem. After all, every minute spent watching a squirrel water-ski is a minute not spent thinking about massive economic inequality, rural unrest, corruption, one-party rule, or what might really be going on in Tibet.

Sina.com, the largest portal in China, is reportedly spending millions of dollars to upgrade its infrastructure in advance of the Olympics to be held this summer in Beijing, when millions of Chinese users are expected to watch the games over the Internet. While the games might seem like a perfectly innocuous thing to air, recent calls for international boycotts or protests over Tibet and other human rights issues could politicize the games more than China would like.

The country will also have to drop many of its filtering restrictions in the Beijing area to accommodate an influx of visitors. Not everyone sees a block on sites like YouTube as no big deal, and China knows it.

Still, it has no plans to back off its aggressive approach to censorship. Now that it has the largest Internet-using population in the world, China seems more determined than ever to exert control over the new medium, even going so far as to require registration at 'Net cafes.

It has to tread carefully, however. Regulations last year designed to make bloggers register their real names with the government were abandoned in the face of popular protest, and even this year's imposition of licenses for Internet broadcast sites included concessions for established (and popular) companies.