It looks like Madonna has another stalker. Despite boasting a top-notch security system, the pop legend’s heavily fortified London mansion was invaded by a stalker over the weekend while she was in the U.S. at her grandmother’s funeral, police said Monday. Grzegorz Matlok, who police say is obsessed with Madonna, got through the security system by merely smashing in a side window. “Something dreadful has happened here,” a senior police source told The Sun newspaper in London. “The security around the world’s most famous pop star should be impregnable.” Madonna’s bodyguards found Matlok going through her things when they tackled him.