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In Pictures: Can your IP address give away your id...
Contacting the conman
John Smith is looking for an independent contractor who conned his elderly parents (took the money, then left town without doing the work). They paid him in cash, so they only knew his first name was Calvin and his business name was Q's Construction. Calvin originally communicated with them through email, which he had already cancelled. But Smith reviewed the headers of the emails and found the man's ISP. With a little more Internet research, Smith located the conman's full and current contact information and then got his parent's money back.
In Pictures: Can your IP address give away your identity?