For Newsnight, a team of independent film-makers has been following some of the members of UK Uncut, a group which calls itself an army of citizen volunteers determined to make wealthy tax avoiders pay.
On Sunday CS spray was used during an arrest of a female UK Uncut protester outside Boots in central London, police have confirmed.
Here are UK Uncut in their own words.
Broadcast on Monday 31 January 2011.
Produced and Directed by Gemma Atkinson & Fred Grace, Fat Rat Films. Edited by Andrew Evans.