Ed Sheeran describes how Taylor Swift prevents her music from leaking

Ed listened to the song he and Taylor did together when someone with a iPad locked in a briefcase played it for him. Taylor has spoken of being paranoid and protective before. In 2014, she only allowed a Rolling Stone interviewer to listen to 1989 through headphones on Taylor's iPhone. She also flew an iPod to the director of Shake it Off to ask if he liked the song and would like to direct the video. Taylor has also spoken of being paranoid that rooms are bugged or that there are cameras following her everywhere, so she only listens to music through headphones and is careful when changing.

Source: Twitter