This is rather worrying – Facebook and MySpace have been sending people’s personal data to advertising companies, breaking promises to consumers that they do not share information without consent, according to a report by The Wall Street Journal.

Apparently the culprits have been sending user names and ID numbers attached to personal profiles, which can be viewed when consumers click on ads.

Among the ad companies receiving the information are Google’s DoubleClick and Yahoo!’s Right Media. Both firms told the Journal that they are were unaware of the data being sent to them and said that have not made use of it.

Typically when a user clicks on an ad on a website, the advertiser is informed of the site from which the consumer has been directed , but is not party to personal information. In the case of the named-and-shamed sites however, advertisers were supplied with information that could direct them to a user’s profile page.

As great a scoop as this is, somehow the revelation comes as little surprise. Facebook of course has been barraged with criticism over its relaxation of data rules; and headlines denouncing it are a day-to-day phenomenon.

It wasn’t just Facebook and MySpace that were caught with their hands fiddling people’s personal details, Digg, Xanga, Hi5 and LiveJournal we also identified by the Journal.

But Facebook betrayed consumer confidentiality to a greater degree, according to the report, by sending the username of the person who had clicked an ad, as well as the name of the name of the Facebook profile they were viewing at the time.

Facebook and its brethren are abusing consumer trust and, so far, are getting off pretty lightly. But the backlash has started and if they continue to treat people so cynically, users will (eventually) cotton on, and will depart in their droves.

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