Six weeks ago Microsoft executives made an unsolicited call to Mr. Bates and Silver Lake's Mr. Durban, said people familiar with the matter.

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People get annoyed when someone calls randomly on a landline, and get outright outraged when an unsolicited call comes in to their cell phone.

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The scam starts with the victim, often an older person, receiving an unsolicited call from someone claiming to be from their bank and suggesting their card needs replacing.

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Prosecutors said PW Marketing violated the 1998 anti-spam law because these unsolicited e-mails were sent without a free call number for recipients to phone to stop additional mailings.

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