Rebecca McKinnion has a long but must-read post, featuring research from Ethan Gutmann, on how Cisco Systems technologies are being used to block the free flow of information in China and to enable the state to monitor its own people without pesky legal restrictions.

Gutmann says:

    The real problem is that the next Tiananmen - in whatever incarnation - is much more likely to fail if Chinese citizens have to fight not only the PLA, but Cisco and Motorola, Microsoft and Intel. And this time, Americans will bear a special responsibility for that failure.
   And I predict that the excuses that we hear from Cisco and Microsoft today (“Microsoft abides by the laws and regulations of each country in which it operates…" - as if the Chinese constitution forbid the word “democracy”) will be remembered as a shameful moment in U.S. corporate history.
    So it’s up to us, activists, journalists, watchdogs, Congress, anyone who’s involved with China, to put pressure on American corporations; shareholder proposals; divestment from university contracts. Make a copy of this brochure and send letters, faxes, emails demanding an explanation. Tell them if the Chinese Communist Party wants to use our technology, it must pay the democracy tax.