David Falso was a familiar figure in the smallish upstate city of Cortland, N.Y., as the owner of Patino Murphy’s bar and Bad Lucy’s Ale House.

But when his e-mail address turned up among hundreds of possible visitors to a child pornography site that was under federal investigation in 2005, the FBI obtained a search warrant and five agents paid a visit, not to Falso’s bars, but to his home on Peaceful Drive.