It was around 9 p.m. on Sunday, July 19, when I received a message through the contact form on KrebsOnSecurity.com that the marital infidelity website AshleyMadison.com had been hacked. The message contained links to confidential Ashley Madison documents, and included a manifesto that said a hacker group calling itself the Impact Team was prepared to leak data on all 37 million users unless Ashley Madison and a sister property voluntarily closed down within 30 days.