Shepard Fairey, who rose to fame and made his mark with his wildly successful and now controversial Obama campaign poster, has left his mark here in Venice as well. During the June international art orgy known as the Venice Biennale, Fairey was brought to a tiny bar in the San Polo quarter near the Rialto Bridge by two Biennale hostesses, according to Guiliano, the bartender at Boteri Cafe.