Graffiti are writing or drawings scribbled, scratched, or sprayed illicitly on a wall or other surface in a public place. Graffiti ranges from simple written words to elaborate wall paintings. Graffiti, consisting of the defacement of public spaces and buildings, remains a nuisance issue for cities. In America around the late 1960s, graffiti was used as a form of expression by political activists, and also by gangs such as the Savage Skulls, La Familia, and Savage Nomads to mark territory. Towards the end of the 1960s, the signatures—tags—of Philadelphia graffitists Cornbread, Cool Earl, Sketch and Topcat 126 started to appear. Cornbread is often cited as one of the earliest practitioner of modern graffiti. Around 1970–71, the center of graffiti innovation moved to New York City, where graffitists following in the wake of TAKI 183, Tracy 168 and PHASE 2 would add their street number to their nickname, "bomb" a train with their work, and let the subway take it "all city"—along with their fame, if it was impressive or simply pervasive enough. Bubble lettering held sway initially among graffitists from the Bronx, though the elaborate writing Tracy 168 dubbed "wildstyle" would come to define the art. The early trendsetters were joined in the 70s by graffitists like Dondi, Zephyr and Lady Pink. Graffiti is one of the four main elements of hip hop culture (along with rapping, DJing, and break dancing). The relationship between graffiti and hip hop culture arises both from early graffitists practicing other aspects of hip-hop, and it's being practiced in areas where other elements of hip hop were evolving as art forms. By the mid-eighties, the form would move from the street to the art world. Jean-Michel Basquiat would abandon his SAMO tag for art galleries, and street art's connections to hip-hop would loosen. Occasional hip hop paeans to graffiti could still be heard throughout the nineties, however, in tracks like the Artifacts' "Wrong Side of Da Tracks", Qwel's "Brick Walls" and Aesop Rock's "No Jumper Cables". (en)