A racketeering conspiracy trial against Huawei started Wednesday in New York.

Federal prosecutors say the Chinese tech company did crimes.

They say Huawei stole technology from American firms.

They say it misused the U.S. financial system.

They also say it helped Iran spy on its people.

Huawei is the world's biggest seller of wireless network gear.

But the U.S. bans it from selling equipment to U.S. carriers.

The U.S. is worried about security.

Canada and Britain have also banned it.

Justice Department lawyer Taylor Stout opened the government's case.

She told the Brooklyn jury that Huawei did many crimes over 20 years.

Defense lawyer Brian Heberlig said the accusations are wrong.

He said prosecutors built their case on a few stories.

He said a small number of Huawei workers did bad things.

Huawei has about 200,000 workers in 170 countries.

He said there was "no blueprint for crime."

The first witness was Parham Baheshti.

He grew up in Iran and became a U.S. citizen in 2000.

He testified that he gave secrets to the U.S. government.

The secrets were about his work with Huawei.

He said he learned about the company in 2009.

At that time, he worked for a small firm.

The firm brought the internet to far parts of Iran.

He said he found it "infuriating."

He realized Huawei was pitching to analyze the Iranian people and their behavior online.

He left Iran in 2011.

He was told he was under investigation.

Heberlig told jurors the prosecution's witnesses were not reliable.

He said some testimony came from "old grudges."

He made fun of a plan.

The plan was to show that a Huawei worker photographed a rival's product at a trade show.

He said Huawei fired the worker for the "foolish act."

He said it was not proof of a companywide conspiracy.

The U.S. announced the criminal charges in early 2019.

It has since added more charges.

Chinese officials have called the U.S. actions "economic bullying."