After his 3-year-old boy became ill from drinking contaminated milk, Zhao Lianhai did what most parents would: he got angry, and he called for action.

Now, he’s facing two-and-a-half years in a Chinese prison, convicted of inciting social disorder, the Associated Press reports.

Zhao’s troubles began in 2008, when his young son was among 300,000 Chinese who drank melamine-laced milk, resulting in six deaths. Zhao’s child survived, but suffered a bout of kidney stones as a result of the contamination, which was one of the worst food-safety scandals in recent Chinese history.

The angry father responded by forming a support group for parents of sickened children, which led to public meetings and protests, and trading of food safety information online. Zhao also called for greater accountability and compensation for parents following the episode.

His efforts earned him the ill-will of the embarrassed Chinese government, which his lawyer says is why he got such a harsh sentence.

“We’d expected it to be much less than that. It is such a harsh sentence,” lawyer Li Fangping told the AP. “The crimes he was accused of were nothing more than what regular citizens would do to defend their rights.”

Human rights groups, including  Amnesty International, condemned the sentence.

“We are appalled that the authorities have imprisoned a man the Chinese public rightly view as a protector of children, not a criminal,” Catherine Baber, Amnesty’s Asia-Pacific deputy director, said.

Zhao, a former reporter, has been behind bars since being taken away by police in November 2009. He said he would appeal the conviction, and promised a hunger strike in protest.

The sentence came down a day before a senior official of the U.S. Food and Drug Administration, speaking in Shanghai, highlighted the challenges posed by efforts to improve food safety in China.