From here:

A skirmish broke out during U2’s performance at Britain’s Glastonbury festival between security guards and protesters unhappy with the group’s tax avoidance in Ireland.

The Art Uncut group inflated a massive balloon emblazoned with the message “U Pay Your Tax 2” during the Irish rock group’s Friday night performance. The statement is a reference to the group members’ decision to move their business affairs in 2006 from Ireland to the Netherlands, which meant they didn’t have to pay taxes in Ireland on their profits.

As the protesters were about to release the balloon over the crowd, they were wrestled to the ground by a security team, who then deflated it and took it away. There were no arrests.

It would be ironic if the security team were funded by tax payers.