Wednesday 15 April 2009 18.59 BST
In the fortnight since the G20 protests in London, the Guardian has received video footage from a number of people that appears to show police using excessive force or questionable tactics in dealing with demonstrators and the press.
The best-known video was sent by a New York fund manager early last week. It shows Ian Tomlinson, who was attempting to return home on the evening of the first day's protests, on 1 April, being pushed to the ground by a police officer.
Here is a list of the footage received over this period, displayed in chronological order according to when the events took place. The Guardian is passing newly obtained footage to the Independent Police Complaints Commission, with the permission of those who shot the films.
Note: Most of the video footage contains violence, and one includes swearing.
1 April, 5.29pm, near Bank, City of London