Several months ago when Twitter introduced its lists feature, social media consultant Allen Mireles checked to see which lists included her. "I wanted to see if the lists I was on were a reflection of how I wanted to be viewed on Twitter," she says. She found two surprises: A porn star had included her on a list and another user listed her under "people I've seen naked"-a surprise, she says, because she had never met the person.

The reputations of organisations are taking a beating in social media, with consumers going so far as to boycott companies based on comments made on sites such as Facebook and Twitter, a new survey has found.