A security researcher is reporting that Pasadena-based matchmaking site Santa Monica-based eHarmony is alerting users to change their passwords, after a reported breach of customer information. According to KrebsonSecurity, an Argentinian hacker who was also responsible for a recent hack of PlentyOfFish.com was the source of the breach, which affected users of eHarmony's advice site. The breach follows a rash of similar security issues from other web-based service providers in the last few months.