The defendant could be sentenced to up to 20 years in prison. Taylor Swift performs onstage at the "Taylor Swift | The Eras Tour" at SoFi Stadium on August 7, 2023 in Los Angeles, California. Michael Buckner/Variety Trending on Billboard A man accused of pledging allegiance to the Islamic State group and plotting to attack one of superstar singer Taylor Swift ’s concerts in Vienna nearly two years ago pleaded guilty as his trial began on Tuesday, his lawyer said. The plot was thwarted, but Austrian authorities still canceled Swift’s three performances in August 2024. The singer’s fans, known as Swifties, who had flown to Austria from across the globe to attend a performance of her record-setting Eras Tour were devastated, but rallied to turn Vienna into a citywide trading post for friendship bracelets and singalongs. Related The defendant, a 21-year-old Austrian citizen known only as Beran A.…