This happened to me once where someone made a payment via my paypal account. I was completely baffled. I always use a unique PayPal password and use secure combinations. They didn't chance my account info or password for that matter. Somehow they get a hold of my password. Eventually, I got my money refunded but this time one person that withdraw money from my account contacted my saying interesting things: "Hi, I found your paypal account on the internet and got logged in. I accidently made a payment using your information. Just want to give you a heads up and warn you. I have requested the money to be send back to you. Sorry" I can imagine this happens all the time. But really?! There is always something that suprizes you.