Statues of Nelson Mandela, Winston Churchill, suffragette Millicent Fawcett, and others in London’s Parliament Square were defaced over the weekend, as trans rights protesters reacted to a UK Supreme Court ruling on the legal definition of “woman.”

The demonstration, sparked by outrage at the decision, targeted the statues with graffiti, according to the Telegraph. Among the messages was “F*ck rights,” scrawled across Fawcett’s statue. Scotland Yard has launched an investigation into the vandalism, which took place during a large protest in Westminster.

Home Secretary Yvette Cooper said: “Criminal damage like this, including to statues of men and women who fought for freedom and justice like Winston Churchill, Nelson Mandela and Millicent Fawcett, is disgraceful.”

The Supreme Court ruling was the result of a seven-year legal challenge from the group For Women Scotland (FWS) against the Scottish government over the definition of gender and sex in the Equality Act of 2010. Following the decision, the women behind FWS say they’ve been hit with a wave of abuse and threats.

One message sent to their email address read: “You’re a group of disgusting murderers and deserve death. God will rip you from your family one day and nobody will mourn you.” Another said: “Your inhumanity makes me vomit. You stupid women should feel deeply ashamed for being so stupid.”

Susan Smith, one of the FWS leaders, said: “It would never occur to us to send messages like this or to call our opponents ugly. But we get this every day.”

Marion Calder added: “Sadly, it is almost inevitable that women who speak up for our rights will be threatened by angry men. It’s a tale as old as the hills. Thankfully, the nastiness is dwarfed by messages of love and support, many of which have brought us to tears.”

Police Scotland have not received a report about the threats, and say they cannot open an investigation unless one is filed.

Metropolitan Police Chief Superintendnt Stuart Bell, who led the weekend’s protest operation, said: “While the police support the public’s right to protest, criminality like this is senseless and unacceptable. We are pursuing this.” Officers are reviewing video fooage from the protest and may take action if any signs or messages violated the law.

Consearvitive MP Robert Jenrick questioned the lack of arrests and enforcement: “The law must be enforced equally. Why have there been no arrests or charges for brazen criminal damage? Until there is proper punishment for criminality like this, people will continue to do it knowing they can get off scot-free.”