MSNBC:

Thousands of cars flying white ribbons or white balloons circled central Moscow on Sunday in a show of protest against Russian Prime Minister Vladimir Putin.
The cars jammed the inner lanes all along the 16-kilometer (nearly 10-mile) Garden Ring, which has as many as 16 lanes of traffic at its widest points. More protesters stood along the side of the road waving white ribbons and flags as the cars passed, their horns blaring.
White ribbons became an opposition symbol during demonstrations to protest alleged fraud in a Dec. 4 parliamentary election said to have boosted the results for Putin's party.