Late last year, a student group that criticizes China's rule in Tibet learned false e-mails were being sent in their name. Their Google-provided e-mail accounts had been hacked.
"I was extremely startled," said Tenzin Seldon of Students for a Free Tibet. "I couldn't believe that someone, an unknown stranger, could hack into my account so easily."
Last week, Google traced the sabotage back to China and says the break-ins were part of a pattern of cyber-attacks on human rights activists who criticize China.
"It's very difficult to tell whether or not these are really Chinese government officials," said Larry Clinton, president of Internet Security Alliance. "More likely they are people who have a loose affiliation with the Chinese government."
Google has had a tense relationship with China ever since it entered the country in 2006. The Chinese government forces Google to censor some search results on Google.cn like the 1989 uprising in Tiananmen Square.
So far, Google has stopped short of accusing the Chinese government of the hack attack. But the company is putting pressure on China to end censorship.
"These attacks ... combined with the attempts over the past year to further limit free speech on the web, have led us to conclude that we are no longer comfortable continuing to censor our results on Google.cn," Google said in a statement.
Translation: Google is threatening to pull out of China if it can't operate freely. On Thursday, the stand off intensified when Secretary of State Hillary Clinton criticized the Chinese government.
"We look to the Chinese authorities to conduct a thorough review of the cyber-intrusions," she said.
In the last quarter, Google took in $150 million from China, just a fraction of the $6 billion it made worldwide. But Google says what's at stake here isn't profits, it's principle and making sure it doesn't lose the trust of its users.