ratemyteacher.co.uk available for pupils to rate their teachers online

Sites such as ratemyteacher.co.uk and bebo give pupils the chance to anonymously praise or castigate their teachers from their own homes. Teachers are clearly disturbed by this development. I don't know what to think, clearly this is something that happened before anyhow by 'word-of-mouth', now to have it digitally preserved could be quite damaging to a teacher's career, and maybe not all allegations made by pupils are fair? I am not sure that I would like to be a teacher today.