For example, protesters in Warsaw used a spy drone last month to see what police were doing. As diydrones.com notes:
People tend to assume that UAVs will be used by the police to keep watch on us, but as … video, taken by a RoboKopter of riots in Warsaw, shows, they can equally be used by citizens to keep tabs on the police. No need to wait for the local news to send a helicopter to get the aerial scene of a demonstration, just Do It Yourself!