Fear can be good for business. Just ask the multibillion-dollar insurance industry,for example. So it comes as no surprise that,after years of headlines and horror stories about predators,cyberbullies and other dangers to children online,a crop of subscription services has emerged to help parents monitor their childs activities on social networks. The new companies include SafetyWeb in Denver; SocialShield,of San Mateo,California; and MyChild,in Redwood City,California. These services scour the Web to create easily digestible reports for parents of everything a child is doing online. The firms charge for subscriptions; the lowest costs $10 a month or $100 a year. For harried parents,the question is: Are they worth it? Certainly not for people who are Web-savvy. But many parents are overwhelmed by the rapid pace of technological change. For these people,a simple Internet cheat sheet on their child could be a useful tool. SafetyWeb and SocialShield both start by asking for information about a child,including his or her e-mail address and the familys physical address. Then they look through various social networks,checking to see where the child has accounts and,where possible,monitoring what the child writes and what others write about the child. Long lists of a childs online activities emerge,some marked as safe,some as potentially dangerous. Other items are explicitly red-flagged,like a Facebook friend who is considerably older,or a posting with a keyword like kill or suicide. There are plenty of reports about innocuous accounts on sites like Amazon and false alarms (the band killed last night). If its good,well tell you about it and if its something to be concerned about,we will tell you as well, said Geoffrey Arone,chief of SafetyWeb. The services look only for material that is publicly available. When it comes to Facebook,often the center of childrens online lives,SafetyWeb takes a more discreet and privacy-respecting approach. It asks parents to link their Facebook account to the service,assuming that they are friends with the child on the site. By contrast,SocialShield asks the child,not the parent,to link his or her Facebook account to the monitoring service. NYT