don't talk to aliens

Stephen Hawking, a British physicist regarded by many as the most famous living scientist, recently was in the news for saying that we should stop trying to contact extraterrestrial intelligent life because it could be dangerous for us. In a documentary for the Discovery Channel he warned, "If aliens visit us, the outcome would be much as when Columbus landed in America, which didn't turn out well for the Native Americans." His argument is that if aliens could come to our planet travelling across light years they must have developed a superior civilization and can easily colonize or destroy us.

http://www.timesonline.co.uk/tol/news/science/space/article7107207.ece

The question is should our quest for knowledge be thwarted by fear of unintended consequences? What if we could benefit from their advanced civilization? What if we stopped splitting the atom fearing that it may lead to nuclear weapons? Is there something as dangerous knowledge?