The famous scam (written about in Lonely Planet and elsewhere) of “Where are you from? My daughter lives there… Let’s go for a drink,” and then you are charged huge sums and threatened — this scam is alive and well by the Akropoli Metro station in the Plaka.
One of the main perpetrators is a very distinguished, elegant-looking older man (in his 70s). He sometimes carries a cane or umbrella and speaks very good English. He tried this on me and failed, but I saw him succeed with a young English traveler a couple of days later. He has colleagues around who look out for him, so if you see this happen, don’t try to interfere.
He stands in the intersection of the street leading uphill from the Akropoli station and the Acropolis promenade (Dionyssiou Areopagitou), which is the entrance to the Acropolis and museum.
There is no danger so long as you just keep walking and don’t accept any invitations from him or his friends.