We now know more about how Google is developing its censored search engine for China. To comply with Chinese authorities, Google has been using search samples from a Beijing-based website it owns to make blacklists, according to The Intercept, which broke news of Google’s work on the censored search engine last week.

While most of Google’s services are blocked in China, its website 265.com remains open. The search engine on 265.com redirects to Baidu, China’s dominant search company, by default, but Google can apparently see the queries that users are typing in.

Google engineers are reportedly sampling those search queries in order to develop a list of thousands of blocked websites it should hide on its upcoming search engine in China. Blacklisted results, which include topics like the Tiananmen Square massacre, will result in users seeing a blank page, The Intercept reports.

Google has essentially been using the site to figure out what Chinese users are searching for since 2008

On Baidu, if you search for something less specific, like Taiwan or Xinjiang, you’ll get a partial blackout where you can only see tourist information and not politically sensitive news reports. It could be possible that Google is taking a similar tack.

Originally, 265.com was founded in 2003 by Chinese entrepreneur Cai Wensheng, who’s also the founder of Chinese beauty app Meitu. Google bought the site in 2008, while it was still operating its search engine within China. Google has essentially been using the site to figure out what Chinese users are searching for since 2008, and now that it is working on an Android search app, it will finally have a use for that data.

After reports surfaced last week of Google’s plans to return to China with a search app, a news app, and potentially cloud services, US employees reacted in anger and confusion. Management shut down access to documents related to the project. And in the meantime, employees are spreading tongue-in-cheek memes related to human rights in China, according to The Intercept. One meme shows a Chinese internet user searching for the Tiananmen Square massacre and getting a result saying it wasn’t real. We’ve reached out to Google for comment.