Kajsa Wahlberg remembers well the reaction when she helped lead efforts to introduce Sweden's now-famous laws criminalising the purchase of sex. "It had enormous interest. People were laughing in 1999 at Sweden and saying it can't be done. A German police officer told me, 'You're crazy sweetie, you can't do that, you cannot prohibit men from buying sex, it's totally impossible.' But he said if you can reduce the amount of trafficking cases with your legislation I wish you good luck, because in Germany it's grown out of proportion."

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