The internet gets a bad reputation because you can meet all sorts of weird people there. People who might not make it past the first "Ewww, they smell funny" in person can slip into one's life in a meeting of intellect as long as they have the courtesy formulae for their section of the internet memorized.
Face to face, you have a meeting of social graces before you have a meeting of minds, and people with the bad social graces get weeded out, and one can still be pleasant with people with good social graces and poor minds.
On the other hand, on the internet one has a meeting of minds before one has a meeting of social graces, so the people with the poor minds (and the poor online social graces) get weeded out first. Upon meeting face-to-face, one still has to weed for social graces.