Brazil's Public Prosecutor's office has launched an inquiry into whether a new Facebook app "offends the honour" of Brazilian men.

The Lulu app allows female users to rate publicly the men they know. It has 3 million users worldwide, and has clocked up half a billion profile views, according to Lulu.

It has led to a national debate in Brazil about sex, decency and privacy. Mukul Devichand of BBC trending reports.

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