This could be the problem:
"Following a large number of complaints from individuals, the Commissioner issued an enforcement notice, ordering the website b4usearch.com to stop using personal information from electoral registers published before 2002, after finding the site in breach of the Data Protection Act.
We issued an enforcement notice against the website, which offers a free 'people search' facility, after receiving over 2000 complaints about the site. "
http://www.ico.gov.uk/tools_and_resources/enew sletter_and_alerts/previous_enewsletters/Engli sh/Edition2.aspx
And of course they can only put entries from the electoral register where people have not ticked the box on the voters form for privacy. This site and similar sites face court action, massive fines and closure if they do not comply.
I tick the box on the voting form, and can't understand why people don't.