(NewsNation) — A Chinese balloon floating over America’s heartland captured national attention last week, but balloons are far from the only tool China has to gather intelligence about the U.S.

FBI Director Chris Wray said the agency has more than 2,000 active investigations into Chinese intelligence-gathering operations and they open a new case roughly every 12 hours.

Here are just a few of the ways China spies on the U.S.

Hacking

China’s cyber efforts include an incident where the country accessed the security files for millions of Americans via computers in the Office of Personnel Management and one where the country accessed medical records from Anthem. China has also gone after travel records for Americans, targeting hotels.

Satellites

Like many countries, China has an array of satellites they can use to collect images for their intelligence agencies. Satellites have a number of advantages over balloons, but they are also more expensive to deploy and use.

Cellphone Towers

Cell phone towers and equipment made by Chinese technology companies can be used to intercept communications. While many major carriers don’t use Chinese-made tech, smaller rural carriers might be tempted by the cheaper technology. That includes those in areas near U.S. military bases and missile silos.

Land Purchases

Chinese companies may buy up large plots of land in strategic locations, specifically near military installations. From there, the country can use technology or people to attempt to gain information. Montana Sen. Jon Tester has sponsored bipartisan legislation to try to prevent China, as well as certain other countries, from purchasing farmland due to concerns about espionage.

Academics

Students and researchers from China may come to the U.S. for legitimate purposes, but the Chinese government may still attempt to use them as influencers to advance Beijing’s agenda.

Technology

TikTok has been under scrutiny as parent company ByteDance previously admitted that employees had gathered data on U.S. users. While some lawmakers have moved to ban the social video app at the state or federal level, the company is reportedly working with Congress to help safeguard user data.

Spies

With all the technology at its disposal, China also continues to rely on old-fashioned human espionage to get information. Chinese spies have been found to be working in the U.S. China’s government has also worked to recruit Americans in positions of power, like law enforcement, to gather information for them. The country has also used attractive female agents to get close to U.S. officials, using sex and romance to ply them for secrets.

China’s attempts to gather information don’t just impact the government, as industrial espionage is also a major goal. It’s a costly one too, with an estimated cost of $200 to $600 billion in intellectual property theft per year, according to acting director of the National Counterintelligence and Security Center Mike Orlando.