Oprah's Tweet Ruffles Nielsen Feathers

Talk show host Oprah Winfrey has fallen foul of Nielsen after tweeting a request to its panelists on Sunday, urging them to watch her cable network OWN instead of the televised Grammy awards.

According to reports in the press, Winfrey specifically asked those with a Nielsen box to switch channels to OWN.

Networks are not allowed to specifically target Nielsen subscribers, and the firm's own policy prohibits 'attempts to single out panel members, to change their viewing habits'.

In a statement provided to Entertainment Weekly magazine, a company representative stated: 'In accordance with our policies and procedures, Nielsen is reviewing this incident with our clients and we may withhold, breakout and/or make a note in the ratings. We take any violation of our policy seriously and will work with clients to resolve the situation.'

Winfrey has since deleted the tweet at Nielsen's request, and apologized for the incident.

Web site: www.nielsen.com .