Taylor Swift threatened to sue the college student who tracks her private jet

• Aircraft-tracking mogul Jack Sweeney said he has received a cease-and-desist notice from Taylor Swift.
• The letter called on Sweeney to stop "stalking and harassing behavior."
• He told Business Insider he does not intend to harm Swift but uses the accounts for "transparency."

Taylor Swift has threatened to take legal action against the college student who tracks her private jet and manages social-media accounts that publish its flights.