That is according to a back-and-forth private Twitter conversation between Musk and University of Central Florida student Jack Sweeney.

Musk, who was named TIME’s 2021 Person of the Year, has been viewed as a polarizing figure in recent years. The billionaire entrepreneur known for Tesla and SpaceX also routinely chimes into political matters, most recently referring to President Joe Biden as a “sock puppet.”

Sweeney, 19, shared the conversation that originated last November with Newsweek.

Musk asked Sweeney to delete the account due to it being “a security risk.”

Musk’s response was in reference to Sweeney’s secondary Twitter account called @ElonJet, which uses software to track all of Musk’s flights in real time. That account has over 127,000 followers.

“Yes I can but it’ll cost you a Model 3 only joking unless?” Sweeney responded, telling Newsweek that he has been a longtime admirer of Musk and that the billionaire’s concerns “are totally reasonable.”

“I put a good amount of time into development and now make some income from it that helps in college,” Sweeney added in the message, saying “it would be nice to get something out of it.”

Sweeney, who possessed some coding experience, told Newsweek he created the tracking account in June 2020.

“I follow Elon Musk on Twitter and I’m a fan of SpaceX and Tesla,” Sweeney said. “I knew when he had the plane and had the idea for a while. I never had the time until COVID.”

In a later message prompted by Musk, Sweeney said he only makes about $20 per month from the tracking account.

After saying that “air traffic control is so primitive” on December 1, Musk asked Sweeney what he can do to stop being tracked.

“I don’t love the idea of being shot by a nutcase,” Musk quipped.

Sweeney’s jet-tracking account involves a bot that utilizes ADS-B data, of which its Twitter page claims it’s “the world’s largest source of open unblocked unfiltered flight data for enthusiasts.”

The UCF freshman told Newsweek that tweets are automatically posted using flight data, but that he also manually writes and publishes some tweets as well.

On January 26 the @ElonJet account posted a map featuring Musk’s flight route, which showed that the jet landed in Austin, Texas.

“The bot takes action on landing and take-off and states the location, state, country and city,” Sweeney said on his website. “Also creates an image of a map of that location and attaches [it] to the tweet. Also calculates and [sic] estimated flight time from takeoff to landing and puts the flight time in the landing tweet.”

When Sweeney told Musk he uses the ADS-B software, Musk replied on December 1.

“OK, how about $5k for this account and generally helping make it slightly harder for crazy people to track me?” Musk said.

“Sounds doable, account and all my help,” Sweeney replied. “Any chance to up that to $50k? It would be great support in college and would possibly allow me to get a car maybe even a Model 3. Would love to help you out.”

Another exchange occurred on December 7 in which Sweeney reached out to quell Musk’s fears. Musk replied, “Thinking about it,” with a thumbs-up emoji.

Eventually, on January 26 Musk sent one last follow-up message to Sweeney: “Doesn’t feel right to pay to shut this down.”

Sweeney told Newsweek he wasn’t sure if Musk conferred with someone else before sending that final message.

“I can still track him,” Sweeney said. “It’s not like the end of the world. It makes it harder.”

For Sweeney, who has gained some programming knowledge and is leaning toward some kind of post-college job position related to software and aviation, the experience to converse with one of the most famous people alive was surreal.

“It was crazy but at the same time it was kind of scary,” he said, adding that Musk “is a nice guy.”

Newsweek reached out to Elon Musk for comment.