I once had a temp job working in an insurance company and one of my many mind numbing jobs was to put different leaflets advertising home insurance or similar in to envelopes and post them out. When I enquired as to where they got all these names and addresses (my junk mail came complete with name) I was told that they were able to get the names and addresses of people who had recently secured planning permission and that they were entitled to do so under the Freedom of Information Act.
These names were supplied to us from somewhere else, they were not sourced in the office and so anybody who called the office to ask that they no longer receive such mail were effectively wasting their time.
I'm pretty sure that such practices would be in breach of current data protection legislation.