Investors aren’t the only ones who like cryptocurrencies – based on the findings of a new report, hackers do as well.

According to Bloomberg – citing Lex Sokolin, global director of FinTech strategy at Autonomous Research – in under 10 years, hackers have been able to steal $1.2 billion worth of bitcoin and Ether. Based on where bitcoin was trading at the end of 2017, the value of the stolen cryptocurrencies would be a lot higher, noted the report.

“It looks like crypto hacking is a $200 million annual revenue industry,” Sokolin said, noting that more than 14 percent of bitcoin and Ether supplies has been compromised by hackers in that timeframe.

Susan Eustis, CEO of WinterGreen Research, noted that hacking cases involving cryptocurrencies have cost companies and governments around the world $11.3 billion in tax revenue from coin sales. Those losses may continue to increase as more investors and companies embrace cryptocurrencies without evaluating the associated risks.

The report noted that while blockchain is supposed to increase transparency, many blockchains began as forks that moved away from existing crypto ledges, which gives hackers new ways to try to manipulate the data. Bloomberg cited a research paper from late December by the Institute of Electrical and Electronics Engineers, which showed how hackers were able to spend the same bitcoin tokens twice.

“We have no evidence that such attacks have already been performed on bitcoin,” the IEEE researchers said in the report. “However, we believe that some of the important characteristics of bitcoin make these attacks practical and potentially highly disruptive.”

Meanwhile, the report pointed to research from security group Cisco Talos, which identified Ethereum vulnerabilities that can result in leaks of sensitive account data.