Cuban artist Tania Bruguera talks about her latest performance work at Tate Modern, Tatlin's Whisper #5, and explains why she's not interested in presenting images that can be viewed at a safe distance, but instead wants people to personally experience the dynamics of power.

Crowd control at Tate Modern. Unwitting gallery-goers were confronted by mounted police who rode back and forth, corralling people and controlling their movements.