In the 70s and 80s, New York City subways were covered in layers of tags and masterpieces of fantastic spray-painted lettering. Even today, as graffiti artists have increasingly joined the mainstream, it’s considered vandalism. However, sociologist and author of Graffiti Lives, Gregory Snyder explains its legacy to the BBC: “There was an opportunity to utilize these young people’s artistic energy in the service of NYC culture,” he says. “And one of the outgrowths of the graffiti movement is that people all over the world came to New York seeking NYC culture – and part of that culture they were seeking was the graffiti written on our subways.” Contemporary street art has gained acceptance as a unique way to make a positive impact on communities. Here are 10 reasons to welcome graffiti artists and public art into your neighborhood.