Bizarrely, people have been known to fall in love (by fall in love, that means the infatuation that people tend to call love) with COMPLETELY fictional characters.... so you don't even get in the showing for extremes.
And, obviously, if one can "fall in love" with someone fictional, then it shouldn't be too hard to fall for someone you've never met. Gotta say I got pretty emotional over one girl I met online.