On Thursday, an Austrian court convicted a man who  had pleaded guilty to plotting an attack at a Vienna concert by the US singer Taylor Swift  in 2024. The 21-year-old, who was also found guilty of forming a terror cell , was sentenced to 15 years in prison. The defendant, identified as Beran A. in accordance with Austrian privacy laws, is an Austrian citizen of North Macedonian descent. Before the court adjourned to consider a verdict on Thursday, he said, "I would just like to say that I am sorry." What do we know about the plot? In April, Beran A. admitted to planning an attack on the Ernst Happel Stadium in Vienna in August 2024. The venue was scheduled to host three performances by the US pop megastar during her "Eras" tour. According to prosecutors, he planned to carry out a jihad-inspired massacre of Swift fans with knives and a bomb . Before the planned attack, Beran A.…