One of the problems with sites on the Net that only sell ads or just collect email addresses to resell, is that the info on their pages is often meant to cause you to provide your email and name for resale.
(see question: http://www.trulia.com/voices/qa/Taunton-Home_Buying-37-36368 )
Getting the info modified is not easy.
I'd spread the word to use actual real estate professionals' sites rather than ones where the correctness of the data is not as important as gathering and selling your name and email to the highest bidders.
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