Brent Scher of the Washington Free Beacon finds irony in one of Democratic presidential candidate Elizabeth Warren’s latest crusades.

As Elizabeth Warren tangles with Facebook CEO Mark Zuckerberg, her presidential campaign continues to use a Facebook tracking tool to quietly record the behavior of its website visitors.

Zuckerberg pledged to “go to the mat” to fight Warren’s plan to break up the social media giant during an internal Facebook meeting. Audio of the meeting released Tuesday set off a flurry of barbs from the Democratic frontrunner. In a Facebook post, Warren pledged to fix the “corrupt system” that allows the tech company to “stomp on consumer privacy rights.”

Warren’s plan to combat Facebook is outlined on her campaign website. The same website, however, contains a hidden Facebook tool called a pixel that enables the campaign to track visitor’s web behavior so it can better target them with ads later.

There is no notification on Warren’s site that a Facebook pixel is installed, but they are easily detected using browser tools such as Ghostery or Facebook’s own “Pixel Helper” plug-in. A Tuesday evening visit to revealed that Facebook’s tracker was one of many placed on the site by her campaign.