Twitter is a strange social media animal in that it seems to occupy both the most serious and most trivial ends of the cultural spectrum.

As we found during the Iranian election of 2009 and then more notably in the Arab Spring, Twitter could be a crucial free speech tool for uniting people and overthrowing oppressive governments. At the same time, Twitter is the domain of Kim Kardashian and Charlie Sheen. Lady Gaga has 6 million more Twitter followers than Barack Obama. A study of Twitter influence in November showed that the actual center of the “Twitterverse” wasn’t Tehran or Cairo or DC or even Zuccotti Park, but Los Angeles.

But yesterday Twitter announced a new change to its platform that’s something of a sacrifice on the free speech side of the spectrum.

The company announced in a blog post that it will start to accommodate the censorship rules of countries’ governments by removing tweets based on controversial content. Twitter says this will allow it to leave the tweets in question uncensored in other countries rather than removing the tweet globally. “Starting today, we give ourselves the ability to reactively withhold content from users in a specific country — while keeping it available in the rest of the world,” the company writes.

But how relevant a tweet by someone organizing protests in Egypt would be to those in other countries isn’t quite clear. There are probably many cases in which there would still be a value to having the tweet live internationally, but censoring it locally kills the platform’s most immediate threat to oppressive governments.

Along with briefly catapulting Charlie Sheen back into the limelight with his #winning and his #tigerblood, Twitter has done some soul searching about free speech over the last year, like resisting the US government’s requests to turn over specific user information. Last year they wrote, “While we may need to release information as required by law, we try to notify Twitter users before handing over their information whenever we can so they have a fair chance to fight the request if they so choose.”

Twitter’s new censorship announcement seems to be a concession to power as the company seeks to expand from 100 million users to a target of 1 billion worldwide. “As we continue to grow internationally, we will enter countries that have different ideas about the contours of freedom of expression,” they wrote yesterday. “Some differ so much from our ideas that we will not be able to exist there. Others are similar but, for historical or cultural reasons, restrict certain types of content,” and they added, no doubt trying to soften the blow, “such as France or Germany, which ban pro-Nazi content.”

Interestingly, Mashable points out that the move may come not from pressure by dictatorial regimes, but from the US: “[War correspondent Mustafa] Kazemi suspects recent calls from members of the U.S. government to remove the Taliban from Twitter are at the root of this policy update.”

For better or worse, Twitter has become a critical communication tool for everything from celebrity nipple slips to political revolution. It’ll be a shame if the company bows to pressure from governments in its pursuit of growth and alters its platform to encourage more nipple slips and less revolution.