Last year I told them I was traveling to Europe and India for two weeks. Found out in London that all their retailers use credit cards with pin numbers. American credit cards without pin numbers are authorized by the discretion of the retailer. Apparently if I use the card and deny making the charges, the merchant is in the hole in UK. Not sure if this is true, this what the pizzaria near Trafalgar Square told me. Anyway there were tons of fraudulent charges from London, mostly airline tickets bought from London to African destinations. Capital reversed ALL the charges from London. Had to call back and tell them the bonafide ones, I didn't want the legitimate businesses to suffer.
So far all the experience I had with credit card companies (Citi, Capital One) or debit cards (Schwab) were uniformly good.
The only minor negative experience was when Citi left a fraud alert phone message that let the cat out of the bag about a surprise Las Vegas trip I had planned for my wife.