Violence broke out in the crowd last night (June 24) at U2’s headline performance at Glastonbury, between security guards and a group of audience members protesting about the band’s handling of their finances.

The Art Uncut group had inflated a huge sign in the crowd with the message "U pay tax 2?" on it. They were protesting at the band's tax affairs, which they called "convoluted". In 2006 the band moved their business affairs from Ireland to the Netherlands, in a switch some believed was made so they could enjoy tax breaks.

http://www.nme.com/news/u2/57554