Would You Let Your 18 Year Old Daughter Travel Alone with a Friend in Europe?

[Emit]

My daughter received a graduation gift from her grandparents - they are taking her and a friend to Europe (Great Britain and France, mostly).

There will be times when the grandparents are off doing their own things, and the two girls will be on their own, max maybe two, three full days. It is uncertain at this time, but they might have to catch their own flight home, without grandparents - we're still working out those details.

Two people have told me, "Don't see the movie, 'Taken'!"

One close family member said, "No, ABSOLUTELY, they can't be alone at all."

I have a big dilemma here. My daughter has wanted to travel for some time, and this is a special opportunity. But I can see the concern of this one family member, and others, who feel it is just too dangerous for young folks now to be alone traveling abroad.

It doesn't help matters at all that this same family member and I traveled to Europe when we I was in my mid 20's and she in her 30's. We were attacked (attempted robbery) in Barcelona when a few Moroccan kids tried to steal my pack. We were pulled into a dark alley way, got beaten up a bit, but were more emotionally scared than physically harmed. (Actually scared the shit out of me, quite frankly.) I don't want that to prejudice my concerns about my own child traveling abroad, though.

Any input?

edit clarity