Anti-government protesters have spilled out into the streets in the British capital London for this year’s “Million Masks March,” using the opportunity to make their voices heard on a wide array of issues, ranging from the UK government’s support for the Israeli government, the US president’s planned state visit to Britain, the rights of migrants and the maladies afflicting the British society.

Organized by the famous hacking collective Anonymous, the peaceful Sunday night rally drew thousands of protesters who wore Guido Fawkes masks, the hacktivist group’s well-known symbol.

Police arrested more than 50 people as the protesters descended on areas including Trafalgar Square, Buckingham Palace and the Houses of Parliament.