Mark Zuckerberg has found a new platform to defend Facebook Inc.’s (FB) business practices.

On Thursday, the under-fire CEO wrote a 1,000-word column in The Wall Street Journal titled "The Facts About Facebook." In the article, Zuckerberg sought to reassure investors and the general public about the social network’s advertising strategy and handling of user data.

Here are five key takeaways from the op-ed:

Advertising is Necessary

Zuckerberg began by justifying the use of advertising on Facebook. The social network was created to give everyone a voice, he said, adding that without ads it would not be possible to make that service free and available to everyone.

Facebook Doesn’t Sell User Data

Facebook’s CEO was keen to assert that working with advertisers doesn’t mean that the social network auctions off user data. Zuckerberg, who admitted that the company’s business model “can feel opaque,” sought to reassure readers that selling people’s data would be counter to Facebook’s interests and even put off advertisers from using the service.

Contrary to what many people believe, Zuckerberg said Facebook simply collects enough data on users to classify them into distinct groups and then charges advertisers to place targeted ads in front of those different categories.

Giving People Control

Zuckerberg also sought to remind Facebook users that they can easily control what information they are shown in ads, and block any advertiser from reaching them. “You can find out why you’re seeing an ad and change your preferences to get ads you’re interested in,” he wrote, adding that this process offers much greater transparency than TV, radio or print. 

Happy to Support Regulation

The Cambridge Analytica scandal has prompted calls to start policing companies such as Facebook. In the column, Zuckerberg said he’s fully supportive of regulation that promotes transparency, choice and control of data and advertising. “We need to be clear about the ways we’re using information, and people need to have clear choices about how their information is used,” he added.

Facebook Isn’t About Clickbait

Facebook has also been criticized for not deleting “harmful or divisive” content immediately. Zuckerberg claimed that not acting faster has nothing to do with driving more engagement and is instead the fault of its imperfect review systems.

“The only reason bad content remains is because the people and artificial-intelligence systems we use to review it are not perfect—not because we have an incentive to ignore it,“ he wrote. Zuckerberg added that negative content in feeds is bad for Facebook as it puts people off using the social network.