Taken from Wikipedia, "his statue has been damaged and defaced many times since the mid-1960s for various reasons, but has been restored each time.
On April 24, 1964, the statue's head was sawn off and stolen by politically oriented artists of the Situationist movement, amongst them Jørgen Nash.[1] The head was never recovered and a new head was produced and placed on the statue.[1] On July 22, 1984, the right arm was sawn off and returned two days later by two young men.[1][9] In 1990, an attempt to sever the statue's head left an 18 centimeters (7 in) deep cut in the neck.[1]
On January 6, 1998, the statue was decapitated again;[9][10] the culprits were never found, but the head was returned anonymously to a nearby television station, and reattached on February 4. On the night of September 10, 2003, the statue was knocked off its base with explosives and later found in the harbour's waters. Holes had been blasted in the mermaid's wrist and knee.[11]
In 2004, the statue was draped in a burqa in a protest against Turkey's application to join the European Union.[12] In May 2007, it was again found draped in Muslim dress and a head scarf.[13]
Paint has been poured on the statue several times, including one episode in 1963 and two in March and May 2007.[9][14] On March 8, 2006, a dildo was attached to the statue's hand, green paint was dumped over it, and the date March 8 were written on it. It is suspected that this vandalism was connected with International Women's Day, which is on March 8.[1]
[15] The statue was found drenched in red paint on May 30, 2017 with the message "Danmark [sic] defend the whales of the Faroe Islands", a reference to whaling in the Faroe Islands (an autonomous country in the Kingdom of Denmark), written on the ground in front of the statue.[16][17] About two weeks later, on June 14, the statue was drenched in blue and white paint. "Befri Abdulle" (Free Abdulle) was written in front of the statue, but it was unclear what this referred to.[18]"