Is there anything Facebook can't do? Yesterday, we wrote about the Dutch woman who is trying to kick drugs by joining the site —in the hope that expanding her social circle beyond addicts will help her succeed. Now comes news that police in Britain are buying ads on Facebook  asking for help in their investigation into a young woman's murder. The body of Bristol architect Joanna Yeates was discovered on Christmas Day, a week after she went missing. She had been strangled. Now, police have launched a national Facebook campaign seeking witnesses. Says detective chief inspector Phil Jones: "The majority of people these days are spending time on Facebook and other social networking sites. This has become part of everyday routine for many people. This advert allows us to point people to special features on our website with all the latest information. It allows them to contact the incident room direct online rather than calling in." The ad directs anyone with information about the case to avonandsomerset.police.uk/jo .