Security experts have devised a system which triggers <A HREF="http://news.bbc.co.uk/1/hi/technology/5397602.stm">a high-pitched screech on a mobile phone</A> if it is stolen. The service is also designed to prevent thieves from using stolen phones and accessing the data contained on them. Under the new system, Remote XT, a signal is sent to the mobile once it is reported lost or stolen, causing it to emit an alarm similar to a scream. The service is backed by the Mobile Industry Crime Action Forum and is aimed at businessmen and women. The alarm noise is accompanied by a message, reading "This phone is stolen".