Elon Musk tweeted that “legal action is being taken” against a Twitter user named Sweeney and other “organizations who supported harm” to his family.

Sweeney ran an account that actively tracked the Twitter CEO’s private jet. Musk’s threat came after he said a “crazy stalker” was following a car carrying his 2-year-old son. He seemed to connect the incident to the flight tracker, which is run by college student Jack Sweeney.

“Last night, car carrying lil X in LA was followed by crazy stalker (thinking it was me), who later blocked car from moving & climbed onto hood,” Musk wrote Wednesday evening.

Musk later shared a video of the alleged stalker and asked, “Anyone recognize this person or car?”

Sweeney’s jet-tracker account and his personal account were both suspended earlier on Wednesday. Sweeney posted a screenshot on Mastodon that showed he was suspended for violating “rules against platform manipulation and spam.”

“Any account doxxing real-time location info of anyone will be suspended, as it is a physical safety violation,” Musk said. “This includes posting links to sites with real-time location info. Posting locations someone traveled to on a slightly delayed basis isn’t a safety problem, so is ok.”

The billionaire said last month that he would not ban Sweeney’s account, explaining that his “commitment to free speech” extended to the account, which has more than 500,000 followers and actively tracks Musk’s location through public flight-tracking data.

At least 25 other accounts tracking billionaires’ private jets were suspended as well, according to the New York Times.