Attempting to discover the answer to a question about a someone's personality or habits by examining their facebook profile and pictures.
Bob: "Does Susan drink?"
Tom: "I don't know. Let's launch an infacetigation."
An attempt to discover information about someone by looking through their Facebook profile and pictures.
Bob:"Does Sheryl drink?"
Tom:"I don't know. Let's launch and infacetigation and look for 'party pics'."