I think many men who use the date rape drug do not have to do it, they simply choose to do it for the sake of convenience and enjoyment.
Consider this: If the date rape drug is administered in a bar that means he has already been interacting with the girl to some degree and is not such a creep that he's been thrown out of the place or is being ignored by all the women there.
If a girl unwisely accepts a drink at a party from a guy atleast he is at the party and talking to her. He is NOT a total loser. He is simply being more efficient about the selection process from a time and energy viewpoint than the law allows.
Van Sloot did get into an altercation with the Mountain Brook students that night.
http://www.scaredmonkeys.com/?p=1102
You seem to be an expert on the subject.
Creepy.