COLLEGE PARK, Md. - As social networks like Facebook, Flickr, Youtube and Twitter increasingly make it possible to access appropriate information within their networks, a whole host of new applications become possible. For individuals, search engines could better differentiate "friends" and suggest groups with more closely matched interests or concerns. Businesses could search allowed information to offer products or services better matched to customers. And national security and counter-terror analysts, with appropriate court authorization, could look for "groups of people within social networks that match certain characteristics.